【作者】 张庆雨； 于蕊； 谢力行； 胡佳媛； 牛立新； 张延龙；

【Author】 ZHANG Qing-yu;YU Rui;XIE Li-hang;HU Jia-yuan;NIU Li-xin;ZHANG Yan-long;College of Landscape Architecture and Arts,Northwest A & F University;

【机构】 西北农林科技大学风景园林艺术学院；

【摘要】 溶血磷脂酸酰基转移酶(LPAAT)是植物种子油脂合成的关键酶。本研究得到1个牡丹LPAAT基因,命名为PrLPAAT4(GenBank登录号为KX256279);该基因开放阅读框(ORF)长度为1116bp,编码371个氨基酸;所编码蛋白含有1个LPLAT_AGPAT-like结构域,预测分子质量为42.9kDa,等电点为8.21,稳定系数为44.70。系统进化树分析结果显示,PrLPAAT4与克莱门柚、毛果杨、木薯和蓖麻LPAAT4基因的亲缘关系较近,氨基酸序列相似度分别达到73.80%、73.91%、71.08%和71.10%。生物信息学分析表明PrLPAAT4包含有3个跨膜区,且有一个跨膜结构与LPLAT_AGPAT-like结构域重叠。信号肽分析发现该蛋白含有信号锚定序列,推测PrLPAAT4为穿膜蛋白。基因结构分析表明代表物种LPAAT4基因均含有3个外显子和2个内含子,且物种间有较高的保守性。亚细胞定位显示35S::PrLPAAT4-GFP融合载体转化后的荧光信号则主要集中在细胞膜上,说明PrLPAAT4是一个细胞膜蛋白。PrLPAAT4基因的表达具有明显的组织特异性,其中种子中的表达量明显高于其他组织。PrLPAAT4基因在种子发育的不同时期均有响应;相关性分析表明,PrLPAAT4基因表达与总脂肪酸含量在S1-S6时期变化趋势基本一致,而伴随种子成熟(S6-S9)二者变化趋势产生差异。克隆得到牡丹PrLPAAT4基因,其编码的蛋白定位于细胞膜上,分析认为该基因在牡丹种子发育中前期的脂肪酸合成过程中发挥作用。更多还原

【Abstract】 Lysophosphatidic acid acyltransferase(LPAAT) is the key enzyme in seeds oil synthesis.The full-length cDNA fragment harboring a 1116 bp ORF encoding a 371 amino acids peptide was named PrLPAAT4.This gene was deposited into GenBank under the accession number KX256279.The ORF of the PrLPAAT4 gene encoded a protein containing LPLAT_ AGPAT-like domain with a calculated molecular mass of 42.9 kDa,an isoelectric point of 8.21 and a stabilization factor of 44.70.The results of phylogenetic trees showed that tree peony LPAAT4 appeared to be more closely related to LPAAT4 of Citrus clementina,Populus trichocarpa,Manihot esculenta and Ricinus communis,and PrLPAAT4 shared 73.80%,73.91%,71.08%and 71.10%amino acid sequence identities with them,respectively.Bioinformatics analysis showed that PrLPAAT4 contained three transmembrane regions,and a transmembrane region structure overlapped with LPLAT_ AGPAT-like domain.The analysis of signal peptide showed that PrLPAAT4 contained an anchor sequence signal,and surmised it was a transmembrane protein.Comparative analysis of gene structure from selected species showed that PrLPAAT4 gene has three exons and two introns,and has higher conservative between species with other species.Results of subcellular localization indicated that the 35 S::PrLPAAT4-GFP chimera was associated with the plasma membrane in the tobacco lower epidermal cells,and these results indicated thatPrLPAAT4 was a plasma membrane protein.The expression of PrLPAATA gene has obvious tissue specificity,the transcript abundance of PrLPAATA was higher in seeds than in other tissues.PrLPAATA was ubiquitously expressed at different stage of seed development Correlation analysis showed that PrLPAATA expression had basic consistency with seed FA accumulation at S1-S6 of seed development However,PrLPAATA expression did not consistently correlate with seed FA accumulation during the late stages(S6-S9) of seed development PrLPAATA gene was cloned from tree peony,and PrLPAAT4 was a plasma membrane protein.Our results showed that PrLPAATA play a role in the fatty acid synthesis of early seed development更多还原