Abstract: Glycerol-3-phosphate acyltransferase(GPAT) is closely related to the plant chill-resistance.Squash(Cucurbita moschata) and figleaf gourd(Cucurbita ficifolia) are close in taxonomy but very different in chill-resistance.The cloning and sequence of figleaf gourd and squash give us a chance to study the relationship between GPAT an dplant chill-resistance in molecular level,from a few different amino-acid residues compared with the two amino-acid sequences.Among thireen different amino acid residues between squash and figleaf gourd ,three of them are the same as those of chill-resistant plants,Arabidopsis thiliana,redflow(Carthamus tinctorius),pea(Pisum sativum ) and spinach(Spinacia oleracea),with may related to the chill-resistant difference of squash and figleaf gourd.

Key words: GPAT, Chill-resistance, Amino-acid

摘要： 甘油-3磷酸转酰酶(GPAT)与植物抗冷性密切相关。南瓜(Cucurbita moschata)与黑子南瓜(Cucurbita ficifolia)同属不同种，亲缘关系较近，但却存在显著的抗冷性差异。南瓜及黑子南瓜GPAT基因的克隆，可以使我们从二者推导的有限氨基酸的差异中对GPAT氨基酸组成及其与植物抗冷性作一定的探讨。发现在南瓜与黑子南瓜13个不同的氨基酸残基中有3个与抗冷性植物拟南芥菜(Arabidopsis thaliana)、豌豆(Pisum sativum)、红花(Carthamus tinctorius)和菠菜(Spinacia oleracea)等相同，可能与黑子南瓜比南瓜更具抗冷性的原因有关。比较南瓜、黑子南瓜、豌豆、红花、拟南芥菜和菠菜等植物中GPAT基因推导的氨基酸序列发现，在比较抗冷的拟南芥菜、红花、豌豆和菠菜等植物中，虽然它们之间的亲缘关系都比较远，但某些位点上的氨基酸残基却完全相同，而与南瓜等抗冷性较差的植物不同，这些位点的氨基酸残基可能也与GPAT对底物酰基的选择性有关。

关键词: 甘油-3磷酸转酰酶(GPAT), 抗冷性, 氨基酸