Reactive oxygen species (ROS) are produced as undesirable by-products of metabolism in various cellular compartments, especially in response to unfavorable environmental conditions, throughout the life cycle of plants. Stress-induced ROS production disrupts normal cellular function and leads to oxidative damage. To cope with excessive ROS, plants are equipped with a sophisticated antioxidative defense system consisting of enzymatic and non-enzymatic components that scavenge ROS or inhibit their harmful effects on biomolecules. Nonetheless, when maintained at relatively low levels, ROS act as signaling molecules that regulate plant growth, development, and adaptation to adverse conditions. Here, we provide an overview of current approaches for detecting ROS. We also discuss recent advances in understanding ROS signaling, ROS metabolism, and the roles of ROS in plant growth and responses to various abiotic stresses.

Calcium oscillations are induced by different stresses. Calcium-dependent protein kinases (CDPKs/CPKs) are one major group of the plant calcium decoders that are involved in various processes including drought response. Some CPKs are calcium-independent. Here, we identified ZmCPK2 as a negative regulator of drought resistance by screening an overexpression transgenic maize pool. We found that ZmCPK2 does not bind calcium, and its activity is mainly inhibited during short term abscisic acid (ABA) treatment, and dynamically changed in prolonged treatment. Interestingly, ZmCPK2 interacts with and is inhibited by calcium-dependent ZmCPK17, a positive regulator of drought resistance, which is activated by ABA. ZmCPK17 could prevent the nuclear localization of ZmCPK2 through phosphorylation of ZmCPK2T60. ZmCPK2 interacts with and phosphorylates and activates ZmYAB15, a negative transcriptional factor for drought resistance. Our results suggest that drought stress-induced Ca²⁺ can be decoded directly by ZmCPK17 that inhibits ZmCPK2, thereby promoting plant adaptation to water deficit.

Excess soil salinity affects large regions of land and is a major hindrance to crop production worldwide. Therefore, understanding the molecular mechanisms of plant salt tolerance has scientific importance and practical significance. In recent decades, studies have characterized hundreds of genes associated with plant responses to salt stress in different plant species. These studies have substantially advanced our molecular and genetic understanding of salt tolerance in plants and have introduced an era of molecular design breeding of salt-tolerant crops. This review summarizes our current knowledge of plant salt tolerance, emphasizing advances in elucidating the molecular mechanisms of osmotic stress tolerance, salt-ion transport and compartmentalization, oxidative stress tolerance, alkaline stress tolerance, and the trade-off between growth and salt tolerance. We also examine recent advances in understanding natural variation in the salt tolerance of crops and discuss possible strategies and challenges for designing salt stress-resilient crops. We focus on the model plant Arabidopsis (Arabidopsis thaliana) and the four most-studied crops: rice (Oryza sativa), wheat (Triticum aestivum), maize (Zea mays), and soybean (Glycine max).

Panicle exsertion is one of the crucial agronomic traits in rice (Oryza sativa). Shortening of panicle exsertion often leads to panicle enclosure and severely reduces seed production. Gibberellin (GA) plays important roles in regulating panicle exsertion. However, the underlying mechanism and the relative regulatory network remain elusive. Here, we characterized the oswrky78 mutant showing severe panicle enclosure, and found that the defect of oswrky78 is caused by decreased bioactive GA contents. Biochemical analysis demonstrates that OsWRKY78 can directly activate GA biosynthesis and indirectly suppress GA metabolism. Moreover, we found OsWRKY78 can interact with and be phosphorylated by mitogen-activated protein kinase (MAPK) kinase OsMAPK6, and this phosphorylation can enhance OsWRKY78 stability and is necessary for its biological function. Taken together, these results not only reveal the critical function of OsWRKY78, but also reveal its mechanism via mediating crosstalk between MAPK and the GA signaling pathway in regulating panicle exsertion.

Precise responses to changes in light quality are crucial for plant growth and development. For example, hypocotyls of shade-avoiding plants typically elongate under shade conditions. Although this typical shade-avoidance response (TSR) has been studied in Arabidopsis (Arabidopsis thaliana), the molecular mechanisms underlying shade tolerance are poorly understood. Here we report that B. napus (Brassica napus) seedlings exhibit dual shade responses. In addition to the TSR, B. napus seedlings also display an atypical shade response (ASR), with shorter hypocotyls upon perception of early-shade cues. Genome-wide selective sweep analysis indicated that ASR is associated with light and auxin signaling. Moreover, genetic studies demonstrated that phytochrome A (BnphyA) promotes ASR, whereas BnphyB inhibits it. During ASR, YUCCA8 expression is activated by early-shade cues, leading to increased auxin biosynthesis. This inhibits hypocotyl elongation, as young B. napus seedlings are highly sensitive to auxin. Notably, two non-canonical AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) repressor genes, BnIAA32 and BnIAA34, are expressed during this early stage. BnIAA32 and BnIAA34 inhibit hypocotyl elongation under shade conditions, and mutations in BnIAA32 and BnIAA34 suppress ASR. Collectively, our study demonstrates that the temporal expression of BnIAA32 and BnIAA34 determines the behavior of B. napus seedlings following shade-induced auxin biosynthesis.

Cultivating high-yield wheat under limited water resources is crucial for sustainable agriculture in semiarid regions. Amid water scarcity, plants activate drought response signaling, yet the delicate balance between drought tolerance and development remains unclear. Through genome-wide association studies and transcriptome profiling, we identified a wheat atypical basic helix-loop-helix (bHLH) transcription factor (TF), TabHLH27-A1, as a promising quantitative trait locus candidate for both relative root dry weight and spikelet number per spike in wheat. TabHLH27-A1/B1/D1 knock-out reduced wheat drought tolerance, yield, and water use efficiency (WUE). TabHLH27-A1 exhibited rapid induction with polyethylene glycol (PEG) treatment, gradually declining over days. It activated stress response genes such as TaCBL8-B1 and TaCPI2-A1 while inhibiting root growth genes like TaSH15-B1 and TaWRKY70-B1 under short-term PEG stimulus. The distinct transcriptional regulation of TabHLH27-A1 involved diverse interacting factors such as TaABI3-D1 and TabZIP62-D1. Natural variations of TabHLH27-A1 influence its transcriptional responses to drought stress, with TabHLH27-A1^Hap-II associated with stronger drought tolerance, larger root system, more spikelets, and higher WUE in wheat. Significantly, the excellent TabHLH27-A1^Hap-II was selected during the breeding process in China, and introgression of TabHLH27-A1^Hap-II allele improved drought tolerance and grain yield, especially under water-limited conditions. Our study highlights TabHLH27-A1's role in balancing root growth and drought tolerance, providing a genetic manipulation locus for enhancing WUE in wheat.

Yield improvement has long been an important task for soybean breeding in the world in order to meet the increasing demand for food and animal feed. miR396 genes have been shown to negatively regulate grain size in rice, but whether miR396 family members may function in a similar manner in soybean is unknown. Here, we generated eight soybean mutants harboring different combinations of homozygous mutations in the six soybean miR396 genes through genome editing with clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated nuclease (Cas) 12SF01 in the elite soybean cultivar Zhonghuang 302 (ZH302). Four triple mutants (mir396aci, mir396acd, mir396adf, and mir396cdf), two quadruple mutants (mir396-abcd and mir396acfi), and two quintuple mutants (mir396abcdf and mir396bcdfi) were characterized. We found that plants of all the mir396 mutants produced larger seeds compared to ZH302 plants. Field tests showed that mir396adf and mir396cdf plants have significantly increased yield in growth zones with relatively high latitude which are suited for ZH302 and moderately increased yield in lower latitude. In contrast, mir396abcdf and mir396bcdfi plants have increased plant height and decreased yield in growth zones with relatively high latitude due to lodging issues, but they are suited for low latitude growth zones with increased yield without lodging problems. Taken together, our study demonstrated that loss-of-function of miR396 genes leads to significantly enlarged seed size and increased yield in soybean, providing valuable germplasms for breeding high-yield soybean.

Thermomorphogenesis and the heat shock (HS) response are distinct thermal responses in plants that are regulated by PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) and HEAT SHOCK FACTOR A1s (HSFA1s), respectively. Little is known about whether these responses are interconnected and whether they are activated by similar mechanisms. An analysis of transcriptome dynamics in response to warm temperature (28℃) treatment revealed that 30 min of exposure activated the expression of a subset of HSFA1 target genes in Arabidopsis thaliana. Meanwhile, a loss-of-function HSFA1 quadruple mutant (hsfa1-cq) was insensitive to warm temperature-induced hypocotyl growth. In hsfa1-cq plants grown at 28℃, the protein and transcript levels of PIF4 were greatly reduced, and the circadian rhythm of many thermomorphogenesis-related genes (including PIF4) was disturbed. Additionally, the nuclear localization of HSFA1s and the binding of HSFA1d to the PIF4 promoter increased following warm temperature exposure, whereas PIF4 overexpression in hsfa1-cq partially rescued the altered warm temperature-induced hypocotyl growth of the mutant. Taken together, these results suggest that HSFA1s are required for PIF4 accumulation at a warm temperature, and they establish a central role for HSFA1s in regulating both thermomorphogenesis and HS responses in Arabidopsis.

Achieving seedlessness in citrus varieties is one of the important objectives of citrus breeding. Male sterility associated with abnormal pollen development is an important factor in seedlessness. However, our understanding of the regulatory mechanism underlying the seedlessness phenotype in citrus is still limited. Here, we determined that the miR159a-DUO1 module played an important role in regulating pollen development in citrus, which further indirectly modulated seed development and fruit size. Both the overexpression of csi-miR159a and the knocking out of DUO1 in Hong Kong kumquat (Fortunella hindsii) resulted in small and seedless fruit phenotypes. Moreover, pollen was severely aborted in both transgenic lines, with arrested pollen mitotic I and abnormal pollen starch metabolism. Through additional cross-pollination experiments, DUO1 was proven to be the key target gene for miR159a to regulate male sterility in citrus. Based on DNA affinity purification sequencing (DAP-seq), RNA-seq, and verified interaction assays, YUC2/YUC6, SS4 and STP8 were identified as downstream target genes of DUO1, those were all positively regulated by DUO1. In transgenic F. hindsii lines, the miR159a-DUO1 module down-regulated the expression of YUC2/ YUC6, which decreased indoleacetic acid (IAA) levels and modulated auxin signaling to repress pollen mitotic I. The miR159a-DUO1 module reduced the expression of the starch synthesis gene SS4 and sugar transport gene STP8 to disrupt starch metabolism in pollen. Overall, this work reveals a new mechanism by which the miR159a- DUO1 module regulates pollen development and elucidates the molecular regulatory network underlying male sterility in citrus.

Plants have evolved complex physical and chemical defense systems that allow them to withstand herbivory infestation. Composed of a complex mixture of very-long-chain fatty acids (VLCFAs) and their derivatives, cuticular wax constitutes the first physical line of defense against herbivores. Here, we report the function of Glossy 8 (ZmGL8), which encodes a 3-ketoacyl reductase belonging to the fatty acid elongase complex, in orchestrating wax production and jasmonic acid (JA)-mediated defenses against herbivores in maize (Zea mays). The mutation of GL8 enhanced chemical defenses by activating the JA-dependent pathway. We observed a trade-off between wax accumulation and JA levels across maize glossy mutants and 24 globally collected maize inbred lines. In addition, we demonstrated that mutants defective in cuticular wax biosynthesis in Arabidopsis thaliana and maize exhibit enhanced chemical defenses. Comprehensive transcriptomic and lipidomic analyses indicated that the gl8 mutant confers chemical resistance to herbivores by remodeling VLCFA-related lipid metabolism and subsequent JA biosynthesis and signaling. These results suggest that VLCFA-related lipid metabolism has a critical role in regulating the trade-offs between cuticular wax and JA-mediated chemical defenses.

Transcriptional regulation plays a key role in the control of seed dormancy, and many transcription factors (TFs) have been documented. However, the mechanisms underlying the interactions between different TFs within a transcriptional complex regulating seed dormancy remain largely unknown. Here, we showed that TF PHYTOCHROME-INTERACTING FACTOR4 (PIF4) physically interacted with the abscisic acid (ABA) signaling responsive TF ABSCISIC ACID INSENSITIVE4 (ABI4) to act as a transcriptional complex to promote ABA biosynthesis and signaling, finally deepening primary seed dormancy. Both pif4 and abi4 single mutants exhibited a decreased primary seed dormancy phenotype, with a synergistic effect in the pif4/abi4 double mutant. PIF4 binds to ABI4 to form a heterodimer, and ABI4 stabilizes PIF4 at the protein level, whereas PIF4 does not affect the protein stabilization of ABI4. Subsequently, both TFs independently and synergistically promoted the expression of ABI4 and NCED6, a key gene for ABA anabolism. The genetic evidence is also consistent with the phenotypic, physiological and biochemical analysis results. Altogether, this study revealed a transcriptional regulatory cascade in which the PIF4–ABI4 transcriptional activator complex synergistically enhanced seed dormancy by facilitating ABA biosynthesis and signaling.

Global climate change-caused drought stress, high temperatures and other extreme weather profoundly impact plant growth and development, restricting sustainable crop production. To cope with various environmental stimuli, plants can optimize the opening and closing of stomata to balance CO₂ uptake for photosynthesis and water loss from leaves. Guard cells perceive and integrate various signals to adjust stomatal pores through turgor pressure regulation. Molecular mechanisms and signaling networks underlying the stomatal movements in response to environmental stresses have been extensively studied and elucidated. This review focuses on the molecular mechanisms of stomatal movements mediated by abscisic acid, light, CO₂, reactive oxygen species, pathogens, temperature, and other phytohormones. We discussed the significance of elucidating the integrative mechanisms that regulate stomatal movements in helping design smart crops with enhanced water use efficiency and resilience in a climate-changing world.

Ubiquitination-mediated protein degradation is integral to plant immunity, with E3 ubiquitin ligases acting as key factors in this process. Here, we report the functions of OsATL32, a plasma membrane-localized Arabidopsis Tóxicos En Levadura (ATL)-type E3 ubiquitin ligase, in rice (Oryza sativa) immunity and its associated regulatory network. We found that the expression of OsATL32 is downregulated in both compatible and incompatible interactions between rice and the rice blast fungus Magnaporthe oryzae. The OsATL32 protein level declines in response to infection by a compatible M. oryzae strain or to chitin treatment. OsATL32 negatively regulates rice resistance to blast and bacterial leaf blight diseases, as well as chitin-triggered immunity. Biochemical and genetic studies revealed that OsATL32 suppresses pathogen-induced reactive oxygen species (ROS) accumulation by mediating ubiquitination and degradation of the ROS- producing OsRac5–OsRbohB module, which enhances rice immunity against M. oryzae. The protein phosphatase PHOSPHATASE AND TENSIN HOMOLOG enhances rice blast resistance by dephosphorylating OsATL32 and promoting its degradation, preventing its negative effect on rice immunity. This study provides insights into the molecular mechanism by which the E3 ligase OsATL32 targets a ROS-producing module to undermine rice immunity.

The soil-nitrogen condition, which differs greatly between paddy fields (mainly in the form of ammonium, NH₄⁺) and dry fields (mainly in the form of nitrate, NO₃^-), is a main environmental factor that drives the adaptive differentiation between upland and lowland rice ecotypes. However, the adaptive differentiation in terms of the nitrogen use efficiency (NUE) between upland and lowland rice has not been well addressed. In this study, we evaluated NUE-related traits among rice landraces as well as the genetic differentiation between NUE- associated genes and quantitative trait loci (QTLs). The japonica upland and lowland rice ecotypes showed large differences in their NUE-related traits such as the absorption ability for NH₄⁺ and NO₃^-. The indica upland and lowland rice exhibited similar performances when cultivated in solutions containing NH₄⁺ or NO₃^- or when planted in paddy or dry fields. However, the indica upland rice possessed a greater ability to absorb NO₃^-. We identified 76 QTLs for 25 measured traits using genome-wide association analysis. The highly differentiated NUE- associated genes or QTLs between ecotypes were rarely shared by japonica and indica subspecies, indicating an independent genetic basis for their soil-nitrogen adaptations. We suggested four genes in three QTLs as the candidates contributing to rice NUE during the ecotypic differentiation. In summary, the soil-nitrogen condition drives the adaptive differentiation of NUE between upland and lowland rice independently within the japonica and indica subspecies. These findings can strengthen our understanding of rice adaptation to divergent soil-nitrogen conditions and have implications for the improvement of NUE.

Rice stripe mosaic virus (RSMV) is an emerging pathogen which significantly reduces rice yields in the southern region of China. It is transmitted by the leafhopper Recilia dorsalis, which overwinters in rice fields. Our field investigations revealed that RSMV infection causes delayed rice heading, resulting in a large number of green diseased plants remaining in winter rice fields. This creates a favorable environment for leafhoppers and viruses to overwinter, potentially contributing to the rapid spread and epidemic of the disease. Next, we explored the mechanism by which RSMV manipulates the developmental processes of the rice plant. A rice heading‐related E3 ubiquitin ligase, Heading date Associated Factor 1 (HAF1), was found to be hijacked by the RSMV‐encoded P6. The impairment of HAF1 function affects the ubiquitination and degradation of downstream proteins, HEADING DATE 1 and EARLY FLOWERING3, leading to a delay in rice heading. Our results provide new insights into the development regulation‐based molecular interactions between virus and plant, and highlights the importance of understanding virus‐vector‐plant tripartite interactions for effective disease management strategies.

Most mechanistic details of chronologically ordered regulation of leaf senescence are unknown. Regulatory networks centered on AtWRKY53 are crucial for orchestrating and integrating various senescence-related signals. Notably, AtWRKY53 binds to its own promoter and represses transcription of AtWRKY53, but the biological significance and mechanism underlying this self-repression remain unclear. In this study, we identified the VQ motif-containing protein AtVQ25 as a cooperator of AtWRKY53. The expression level of AtVQ25 peaked at mature stage and was specifically repressed after the onset of leaf senescence. AtVQ25-overexpressing plants and atvq25 mutants displayed precocious and delayed leaf senescence, respectively. Importantly, we identified AtWRKY53 as an interacting partner of AtVQ25. We determined that interaction between AtVQ25 and AtWRKY53 prevented AtWRKY53 from binding to W-box elements on the AtWRKY53 promoter and thus counteracted the self-repression of AtWRKY53. In addition, our RNA-sequencing data revealed that the AtVQ25-AtWRKY53 module is related to the salicylic acid (SA) pathway. Precocious leaf senescence and SA-induced leaf senescence in AtVQ25-overexpressing lines were inhibited by an SA pathway mutant, atsid2, and NahG transgenic plants; AtVQ25-overexpressing/atwrky53 plants were also insensitive to SA-induced leaf senescence. Collectively, we demonstrated that AtVQ25 directly attenuates the self-repression of AtWRKY53 during the onset of leaf senescence, which is substantially helpful for understanding the timing of leaf senescence onset modulated by AtWRKY53.

Soil salinity has a major impact on rice seed germination, severely limiting rice production. Herein, a rice germination defective mutant under salt stress (gdss) was identified by using chemical mutagenesis. The GDSS gene was detected via MutMap and shown to encode potassium transporter OsHAK9. Phenotypic analysis of complementation and mutant lines demonstrated that OsHAK9 was an essential regulator responsible for seed germination under salt stress. OsHAK9 is highly expressed in germinating seed embryos. Ion contents and non-invasive micro-test technology results showed that OsHAK9 restricted K⁺ efflux in salt-exposed germinating seeds for the balance of K⁺/Na⁺. Disruption of OsHAK9 significantly reduced gibberellin 4 (GA₄) levels, and the germination defective phenotype of oshak9a was partly rescued by exogenous GA₃ treatment under salt stress. RNA sequencing (RNA-seq) and real-time quantitative polymerase chain reaction analysis demonstrated that the disruption of OsHAK9 improved the GA-deactivated gene OsGA2ox7 expression in germinating seeds under salt stress, and the expression of OsGA2ox7 was significantly inhibited by salt stress. Null mutants of OsGA2ox7 created using clustered, regularly interspaced, short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9 approach displayed a dramatically increased seed germination ability under salt stress. Overall, our results highlight that OsHAK9 regulates seed germination performance under salt stress involving preventing GA degradation by mediating OsGA2ox7, which provides a novel clue about the relationship between GA and OsHAKs in rice.

Leaf senescence is an essential physiological process related to grain yield potential and nutritional quality. Green leaf duration (GLD) after anthesis directly reflects the leaf senescence process and exhibits large genotypic differences in common wheat; however, the underlying gene regulatory mechanism is still lacking. Here, we identified TaNAM-A1 as the causal gene of the major loci qGLD-6A for GLD during grain filling by map-based cloning. Transgenic assays and TILLING mutant analyses demonstrated that TaNAM-A1 played a critical role in regulating leaf senescence, and also affected spike length and grain size. Furthermore, the functional divergences among the three haplotypes of TaNAM-A1 were systematically evaluated. Wheat varieties with TaNAM-A1d (containing two mutations in the coding DNA sequence of TaNAM-A1) exhibited a longer GLD and superior yield-related traits compared to those with the wild type TaNAM-A1a. All three haplotypes were functional in activating the expression of genes involved in macromolecule degradation and mineral nutrient remobilization, with TaNAM-A1a showing the strongest activity and TaNAM-A1d the weakest. TaNAM-A1 also modulated the expression of the senescence-related transcription factors TaNAC-S-7A and TaNAC016-3A. TaNAC016-3A enhanced the transcriptional activation ability of TaNAM-A1a by protein-protein interaction, thereby promoting the senescence process. Our study offers new insights into the fine-tuning of the leaf functional period and grain yield formation for wheat breeding under various geographical climatic conditions.

The heading date of rice is a crucial agronomic characteristic that influences its adaptability to different regions and its productivity potential. Despite the involvement of WRKY transcription factors in various biological processes related to development, the precise mechanisms through which these transcription factors regulate the heading date in rice have not been well elucidated. The present study identified OsWRKY11 as a WRKY transcription factor which exhibits a pivotal function in the regulation of the heading date in rice through a comprehensive screening of a clustered regularly interspaced palindromic repeats (CRISPR)-CRISPR-associated nuclease 9 mutant library that specifically targets the WRKY genes in rice. The heading date of oswrky11 mutant plants and OsWRKY11-overexpressing plants was delayed compared with that of the wild-type plants under short-day and long-day conditions. Mechanistic investigation revealed that OsWRKY11 exerts dual effects on transcriptional promotion and suppression through direct and indirect DNA binding, respectively. Under normal conditions, OsWRKY11 facilitates flowering by directly inducing the expression of OsMADS14 and OsMADS15. The presence of elevated levels of OsWRKY11 protein promote formation of a ternary protein complex involving OsWRKY11, Heading date 1 (Hd1), and Days to heading date 8 (DTH8), and this complex then suppresses the expression of Ehd1, which leads to a delay in the heading date. Subsequent investigation revealed that a mild drought condition resulted in a modest increase in OsWRKY11 expression, promoting heading. Conversely, under severe drought conditions, a significant upregulation of OsWRKY11 led to the suppression of Ehd1 expression, ultimately causing a delay in heading date. Our findings uncover a previously unacknowledged mechanism through which the transcription factor OsWRKY11 exerts a dual impact on the heading date by directly and indirectly binding to the promoters of target genes.

湿地植物生物量对环境因素高度敏感，在土壤有机碳(SOC)库的动态中起着至关重要的作用。本研究中，我们收集并分析了1980至2021年全球湿地植物生物量数据。通过检查182篇已发表的湿地生态系统论文中的1134个观测结果，我们创建了湿地植物地上生物量(AGB)和地下生物量(BGB)的综合数据库。我们利用该数据库分析了全球不同气候带、湿地类型和植物物种的生物量特征。在此基础上，我们分析了不同植物物种生物量的差异以及AGB和BGB与有机碳的联系。我们的研究表明，湿地植物AGB在赤道地区较高，但BGB在极地地区最高，在干旱和赤道地区最低。对于植物种类来说，禾本科植物的BGB高于AGB，但石竹目、莎草目和唇形科的AGB较高。此外，我们的研究结果还发现，与AGB相比，BGB在对有机碳库的贡献方面发挥着更重要的作用。值得注意的是，当BGB小于1 t C ha⁻¹时，即使生物量发生微小变化也会对有机碳库产生重大影响。我们观察到，当BGB含量较低时，SOC增加了5.7 t C ha⁻¹，这表明SOC对生物量的变化在这种情况下更加敏感。我们的研究为湿地植物地上和地下生物量对有机碳的全球响应提供了基础。

丛枝菌根真菌(arbuscular mycorrhizal fungi, AMF)能够提高植物对非生物胁迫(如盐碱)的耐受性,并改善作物产量。然而,这种影响是不稳定的,导致这种变异的原因仍不清楚。本研究旨在评估干旱如何改变AMF对植物抵抗高钙盐胁迫的影响,采用盆栽实验探究AMF接种如何影响玉米在高钙胁迫和两种水分条件下的生长、光合、养分吸收以及C:N:P化学计量比。结果显示,高钙胁迫显著降低了菌根侵染率、生物量积累、C同化速率以及植物组织中的C:N化学计量比。此外,干旱进一步加剧了钙胁迫对光合作用的抑制。在干旱和钙盐胁迫下,AMF接种在很大程度上缓解了这些负面效应。然而,在充足灌溉条件下,当受到高钙胁迫时,AMF几乎不影响玉米的生长。此外,水分影响了AMF对植物组织中养分分配的调控。在充足水分条件下,AMF刺激了根部的P积累和植物生长,但未造成叶片P与C/N比的增长,导致在高钙胁迫下叶片C:P和N:P增加。相反,在干旱条件下,AMF降低了叶片N含量和N:P比。总体而言,AMF通过增强光合作用和调节养分化学计量,提高了玉米对钙盐的抵抗力,这种效应在水分亏缺条件下更为显著。该研究结果强调AMF在复合胁迫下碳同化和养分稳态调控中的调节作用,并为在盐碱和干旱地区作物产量提升提供了科学依据。

Leaves are the main photosynthesis organ that directly determines crop yield and biomass. Dissecting the regulatory mechanism of leaf development is crucial for food security and ecosystem turn-over. Here, we identified the novel function of R2R3-MYB transcription factors CsRAXs in regulating cucumber leaf size and fruiting ability. Csrax5 single mutant exhibited enlarged leaf size and stem diameter, and Csrax1/2/5 triple mutant displayed further enlargement phenotype. Overexpression of CsRAX1 or CsRAX5 gave rise to smaller leaf and thinner stem. The fruiting ability of Csrax1/2/5 plants was significantly enhanced, while that of CsRAX5 overexpression lines was greatly weakened. Similarly, cell number and free auxin level were elevated in mutant plants while decreased in overexpression lines. Biochemical data indicated that CsRAX1/5 directly promoted the expression of auxin glucosyltransferase gene CsUGT74E2. Therefore, our data suggested that CsRAXs function as repressors for leaf size development by promoting auxin glycosylation to decrease free auxin level and cell division in cucumber. Our findings provide new gene targets for cucumber breeding with increased leaf size and crop yield.

The plant hormone jasmonate (JA) regulates plant growth and immunity by orchestrating a genome-wide transcriptional reprogramming. In the resting stage, JASMONATE-ZIM DOMAIN (JAZ) proteins act as main repressors to regulate the expression of JA-responsive genes in the JA signaling pathway. However, the mechanisms underlying de-repression of JA-responsive genes in response to JA treatment remain elusive. Here, we report two nuclear factor Y transcription factors NF-YB2 and NF-YB3 (thereafter YB2 and YB3) play key roles in such de-repression in Arabidopsis. YB2 and YB3 function redundantly and positively regulate plant resistance against the necrotrophic pathogen Botrytis cinerea, which are specially required for transcriptional activation of a set of JA-responsive genes following inoculation. Furthermore, YB2 and YB3 modulated their expression through direct occupancy and interaction with histone demethylase Ref6 to remove repressive histone modifications. Moreover, YB2 and YB3 physically interacted with JAZ repressors and negatively modulated their abundance, which in turn attenuated the inhibition of JAZ proteins on the transcription of JA-responsive genes, thereby activating JA response and promoting disease resistance. Overall, our study reveals the positive regulators of YB2 and YB3 in JA signaling by positively regulating transcription of JA-responsive genes and negatively modulating the abundance of JAZ proteins.

Stomata play a crucial role in plants by controlling water status and responding to drought stress. However, simultaneously improving stomatal opening and drought tolerance has proven to be a significant challenge. To address this issue, we employed the OnGuard quantitative model, which accurately represents the mechanics and coordination of ion transporters in guard cells. With the guidance of OnGuard, we successfully engineered plants that overexpressed the main tonoplast Ca²⁺‐ATPase gene, ACA11, which promotes stomatal opening and enhances plant growth. Surprisingly, these transgenic plants also exhibited improved drought tolerance due to reduced water loss through their stomata. Again, OnGuard assisted us in understanding the mechanism behind the unexpected stomatal behaviors observed in the ACA11 overexpressing plants. Our study revealed that the overexpression of ACA11 facilitated the accumulation of Ca²⁺ in the vacuole, thereby influencing Ca²⁺ storage and leading to an enhanced Ca²⁺ elevation in response to abscisic acid. This regulatory cascade finely tunes stomatal responses, ultimately leading to enhanced drought tolerance. Our findings underscore the importance of tonoplast Ca²⁺‐ATPase in manipulating stomatal behavior and improving drought tolerance. Furthermore, these results highlight the diverse functions of tonoplast‐localized ACA11 in response to different conditions, emphasizing its potential for future applications in plant enhancement.

The development of flowers in soybean (Glycine max) is essential for determining the yield potential of the plant. Gene silencing pathways are involved in modulating flower development, but their full elucidation is still incomplete. Here, we conducted a forward genetic screen and identified an abnormal flower mutant, deformed floral bud1‐1 (Gmdfb1‐1), in soybean. We mapped and identified the causal gene, which encodes a member of the armadillo (ARM)‐repeat superfamily. Using small RNA sequencing (sRNA‐seq), we found an abnormal accumulation of small interfering RNAs (siRNAs) and microRNA (miRNAs) in the Gmdfb1 mutants. We further demonstrated that GmDFB1 interacts with the RNA exosome cofactor SUPER KILLER7 (GmSKI7). Additionally, GmDFB1 interacts with the PIWI domain of ARGONAUTE 1 (GmAGO1) to inhibit the cleavage efficiency on the target genes of sRNAs. The enhanced gene silencing mediated by siRNA and miRNA in the Gmdfb1 mutants leads to the downregulation of their target genes associated with flower development. This study revealed the crucial role of GmDFB1 in regulating floral organ identity in soybean probably by participating in two distinct gene silencing pathways.

Coordinated morphogenic adaptation of growing plants is critical for their survival and propagation under fluctuating environments. Plant morphogenic responses to light and warm temperatures, termed photomorphogenesis and thermomorphogenesis, respectively, have been extensively studied in recent decades. During photomorphogenesis, plants actively reshape their growth and developmental patterns to cope with changes in light regimes. Accordingly, photomorphogenesis is closely associated with diverse growth hormonal cues. Notably, accumulating evidence indicates that light-directed morphogenesis is profoundly affected by two recently identified phytochemicals, karrikins (KARs) and strigolactones (SLs). KARs and SLs are structurally related butenolides acting as signaling molecules during a variety of developmental steps, including seed germination. Their receptors and signaling mediators have been identified, and associated working mechanisms have been explored using gene-deficient mutants in various plant species. Of particular interest is that the KAR and SL signaling pathways play important roles in environmental responses, among which their linkages with photomorphogenesis are most comprehensively studied during seedling establishment. In this review, we focus on how the phytochemical and light signals converge on the optimization of morphogenic fitness. We also discuss molecular mechanisms underlying the signaling crosstalks with an aim of developing potential ways to improve crop productivity under climate changes.

Dormancy is an adaptive trait which prevents seeds from germinating under unfavorable environmental conditions. Seeds with weak dormancy undergo pre-harvest sprouting (PHS) which decreases grain yield and quality. Understanding the genetic mechanisms that regulate seed dormancy and resistance to PHS is crucial for ensuring global food security. In this study, we illustrated the function and molecular mechanism of TaSRO1 in the regulation of seed dormancy and PHS resistance by suppressing TaVP1. The tasro1 mutants exhibited strong seed dormancy and enhanced resistance to PHS, whereas the mutants of tavp1 displayed weak dormancy. Genetic evidence has shown that TaVP1 is epistatic to TaSRO1. Biochemical evidence has shown that TaSRO1 interacts with TaVP1 and represses the transcriptional activation of the PHS resistance genes TaPHS1 and TaSdr. Furthermore, TaSRO1 undermines the synergistic activation of TaVP1 and TaABI5 in PHS resistance genes. Finally, we highlight the great potential of tasro1 alleles for breeding elite wheat cultivars that are resistant to PHS.

AUXIN RESPONSE FACTOR 7 (ARF7)‐mediated auxin signaling plays a key role in lateral root (LR) development by regulating downstream LATERAL ORGAN BOUNDARIES DOMAIN (LBD) transcription factor genes, including LBD16, LBD18, and LBD29. LBD proteins are believed to regulate the transcription of downstream genes as homodimers or heterodimers. However, whether LBD29 forms dimers with other proteins to regulate LR development remains unknown. Here, we determined that the Arabidopsis thaliana (L.) Heynh. MYB transcription factors MYB2 and MYB108 interact with LBD29 and regulate auxin‐induced LR development. Both MYB2 and MYB108 were induced by auxin in an ARF7‐dependent manner. Disruption of MYB2 by fusion with an SRDX domain severely affected auxin‐induced LR formation and the ability of LBD29 to induce LR development. By contrast, overexpression of MYB2 or MYB108 resulted in greater LR numbers, except in the lbd29 mutant background. These findings underscore the interdependence and importance of MYB2, MYB108, and LBD29 in regulating LR development. In addition, MYB2–LBD29 and MYB108–LBD29 complexes promoted the expression of CUTICLE DESTRUCTING FACTOR 1 (CDEF1), a member of the GDSL (Gly‐Asp‐Ser‐Leu) lipase/ esterase family involved in LR development. In summary, this study identified MYB2–LBD29 and MYB108–LBD29 regulatory modules that act downstream of ARF7 and intricately control auxin‐mediated LR development.

Secondary vascular tissue (SVT) development and regeneration are regulated by phytohormones. In this study, we used an in vitro SVT regeneration system to demonstrate that gibberellin (GA) treatment significantly promotes auxin-induced cambium reestablishment. Altering GA content by overexpressing or knocking down ent-kaurene synthase (KS) affected secondary growth and SVT regeneration in poplar. The poplar DELLA gene GIBBERELLIC ACID INSENSITIVE (PtoGAI) is expressed in a specific pattern during secondary growth and cambium regeneration after girdling. Overexpression of PtoGAI disrupted poplar growth and inhibited cambium regeneration, and the inhibition of cambium regeneration could be partially restored by GA application. Further analysis of the PtaDR5:GUS transgenic plants, the localization of PIN-FORMED 1 (PIN1) and the expression of auxin-related genes found that an additional GA treatment could enhance the auxin response as well as the expression of PIN1, which mediates auxin transport during SVT regeneration. Taken together, these findings suggest that GA promotes cambium regeneration by stimulating auxin signal transduction.

Achieving high yield and good quality in crops is essential for human food security and health. However, there is usually disharmony between yield and quality. Seed storage protein (SSP) and starch, the predominant components in cereal grains, determine yield and quality, and their coupled synthesis causes a yield–quality trade-off. Therefore, dissection of the underlying regulatory mechanism facilitates simultaneous improvement of yield and quality. Here, we summarize current findings about the synergistic molecular machinery underpinning SSP and starch synthesis in the leading staple cereal crops, including maize, rice and wheat. We further evaluate the functional conservation and differentiation of key regulators and specify feasible research approaches to identify additional regulators and expand insights. We also present major strategies to leverage resultant information for simultaneous improvement of yield and quality by molecular breeding. Finally, future perspectives on major challenges are proposed.

Flowering time and maturity are crucial agronomic traits that affect the regional adaptability of soybean plants. The development of soybean cultivars with early maturity adapted to longer days and colder climates of high latitudes is very important for ensuring normal ripening before frost begins. FUL belongs to the MADS‐box transcription factor family and has several duplicated members in soybeans. In this study, we observed that overexpression of GmFULc in the Dongnong 50 cultivar promoted soybean maturity, while GmFULc knockout mutants exhibited late maturity. Chromatin immunoprecipitation sequencing (ChIP‐seq) and RNA sequencing (RNA‐seq) revealed that GmFULc could bind to the CArG, bHLH and homeobox motifs. Further investigation revealed that GmFULc could directly bind to the CArG motif in the promoters of the GmZTL3 and GmZTL4 genes. Overexpression of GmZTL4 promoted soybean maturity, whereas the ztl4 mutants exhibited delayed maturity. Moreover, we found that the cis element box 4 motif of the GmZTL4 promoter, a motif of light response elements, played an important role in controlling the growth period. Deletion of this motif shortened the growth period by increasing the expression levels of GmZTL4. Functional investigations revealed that short‐day treatment promoted the binding of GmFULc to the promoter of GmZTL4 and inhibited the expression of E1 and E1Lb, ultimately resulting in the promotion of flowering and early maturation. Taken together, these findings suggest a novel photoperiod regulatory pathway in which GmFULc directly activates GmZTL4 to promote earlier maturity in soybean.

研究不同海拔地区植物共有种叶片化学计量的变化及其影响因素和适应策略,对于理解全球环境变化中的生物地球化学循环具有重要意义。在本研究中,我们测量了中国西北部祁连山5个海拔高度(海拔2400-3200 m,间隔200 m)的土壤有机碳和养分浓度,以及植物共有种的叶片化学计量,以期能更好地了解山区植物共有种如何对海拔变化表现出适应性反应及未来潜在的环境变化如何影响其叶片功能。研究结果表明,随海拔高度的增加,植物共有种叶片C:N:P化学计量的变化不同。在不同的海拔梯度上,年平均气温(MAT)、土壤全磷(STP)、年平均降水量(MAP)、土壤含水量(SWC)和土壤硝态氮(NO₃^-N)是影响植物共有种叶片元素浓度的主要因素。而叶片化学计量比主要由 MAT、MAP 和土壤全氮(STN)决定。MAT和MAP对植物共有种叶片元素浓度和叶化学计量比均有显著影响。研究区植物生长主要受到磷的限制。研究结果不仅凸显了植物的可塑性生存策略,还有助于加深我们对植物叶片化学计量学的理解,建立单个植物物种和植物群落与共有种之间的联系。

Pathogens generate and secrete effector proteins to the host plant cells during pathogenesis to promote virulence and colonization. If the plant carries resistance (R) proteins that recognize pathogen effectors, effector‐triggered immunity (ETI) is activated, resulting in a robust immune response and hypersensitive response (HR). The bipartite effector AvrRps4 from Pseudomonas syringae pv. pisi has been well studied in terms of avirulence function. In planta , AvrRps4 is processed into two parts. The C‐terminal fragment of AvrRps4 (AvrRps4^C) induces HR in turnip and is recognized by the paired resistance proteins AtRRS1/AtRPS4 in Arabidopsis. Here, we show that AvrRps4^C targets a group of Arabidopsis WRKY, including WRKY46, WRKY53, WRKY54, and WRKY70, to induce its virulence function. Indeed, AvrRps4^C suppresses the general binding and transcriptional activities of immune‐positive regulator WRKY54 and WRKY54‐mediated resistance. AvrRps4^C interferes with WRKY54's binding activity to target gene SARD1 in vitro, suggesting WRKY54 is sequestered from the SARD1 promoter by AvrRps4^C. Through the interaction of AvrRps4^C with four WRKYs, AvrRps4 enhances the formation of homo‐/ heterotypic complexes of four WRKYs and sequesters them in the cytoplasm, thus inhibiting their function in plant immunity. Together, our results provide a detailed virulence mechanism of AvrRps4 through its C‐terminus.