论文部分内容阅读
利用RT PCR结合RACE技术从‘玉露’桃果实中克隆得到△~1-吡咯啉-5-羧酸合成酶(P5CS)和鸟氨酸转氨酶(OAT)基因的全长cDNA序列,分别命名为PpP5CS和PpOAT(GenBank登录号分别为KP973954和KP973956)。PpP5CS全长2511bp,开放阅读框为2 151 bp,编码717个氨基酸组成的蛋白质多肽,5’-UTR长度为123 bp,3’-UTR序列长度为235 bp;PpOAT全长1686 bp,开放阅读框1416 bp,编码472个氨基酸,5’-UTR长度为151 bp,3’-UTR序列长度为119 bp。进化树分析发现,PpOAT和PpP5CS与湖北海棠的同源性最高,与MhOAT和MhP5CS的相似性分别达到88%和91%。采用荧光定量PCR分析了外源5 mmol·L~(-1)GABA处理对桃果实0℃贮藏期间果实冷害发生和内源脯氨酸合成关键基因PpOAT和PpP5CS表达的影响。结果表明,GABA处理能显著抑制‘玉露’桃果实0℃贮藏期间果肉出汁率的下降,减轻冷害。通过上调果实中PpOAT和PpP5CS的表达,提高内源脯氨酸的合成和积累,进而增强了果实抵抗低温胁迫的能力,可能是外源GABA处理减轻桃果实冷害的重要原因。
The full-length cDNA sequences of △ ~ 1-pyrroline-5-carboxylic acid synthase (P5CS) and ornithine aminotransferase (OAT) genes were cloned by RT PCR and RACE from peach fruits of Jade Lu, and named as PpP5CS And PpOAT (GenBank accession numbers KP973954 and KP973956, respectively). PpP5CS full length 2511bp, open reading frame of 2 151 bp, encoding protein polypeptide consisting of 717 amino acids, 5’-UTR length of 123 bp, 3’-UTR sequence length of 235 bp; PpOAT full length 1686 bp, open reading frame 1416 bp encoding a protein of 472 amino acids. The length of 5’-UTR was 151 bp and the length of 3’-UTR was 119 bp. Phylogenetic tree analysis showed that PpOAT and PpP5CS had the highest homology with Begonia camptotheca acuminata and the similarity with MhOAT and MhP5CS was 88% and 91% respectively. The effect of exogenous 5 mmol·L -1 GABA treatment on the chilling injury and the expression of PpOAT and PpP5CS genes in peaches during storage at 0 ℃ was analyzed by fluorescence quantitative PCR. The results showed that GABA treatment could significantly inhibit the decline of jujube fruit juice yield and reduce the chilling damage during storage at 0 ℃. Increasing the expression of PpOAT and PpP5CS in fruits can increase the synthesis and accumulation of endogenous proline, which in turn enhances the ability of fruits to resist cold stress, which may be one of the important reasons for exogenous GABA treatment to reduce chilling injury in peaches.