野生大豆P5CS基因的克隆及对盐胁迫反应

逆境下植物大量积累脯氨酸是减轻胁迫伤害的一种自我保护机制。本研究应用同源克隆方法从NaCl处理的野生大豆中克隆获得一个脯氨酸合成酶(P5CS)基因,命名为GsP5CS。该基因核苷酸序列全长2.232 kb,含一个2148bp开放阅读框,编码715个氨基酸,包含有高等植物P5CS蛋白质的5个主要功能域,与菜豆PvP5CS1基因核苷酸序列相似性高达98.79%。Real Time PCR分析显示该基因受轻度盐胁迫诱导上调表达,根中表达高峰出现在200 mmol/L NaCl处理下,相对表达量为对照的5.83倍;叶片中表达高峰出现在300 mmol/L NaCl处理条件下,相对表达量为对照的12.78倍。并且该基因在根和叶片中的表达模式和脯氨酸含量的变化模式相同。上述结果说明,GsP5CS可能参与野生大豆脯氨酸合成。

Cloning and Expression Analysis of P5CS Gene from Wild Soybean (Glycine soja) seedling under Salt Stress

Free proline accumulation in plant tissues is a self-protection mechanism protecting plant from abiotic stresses. A P5CS gene was cloned using a candidate gene approach from wild soybean seeding treated with NaCl. Sequence analysis showed that, the full-length cDNA sequence is 2,232 kb, containing an open reading frame of 2148bp, encoding 715 amino acids. The cDNA sequence shared 98.79% similarity with PvP5CS1 from common bean. Real Time PCR analysis showed that the gene was significantly induced up-regulated expression by salt stress, the relative expression of the gene reached to the maximum at 200 mM NaCl treatment in roots and 300 mM NaCl treatment in leaves. And the expression models of GsP5CS gene were similar with the proline accumulation models in leave and root of wild soybean treated with different concentration NaCl. The above results showed that the cDNA sequence obtained in this study was the proline synthetase gene of wild soybean (Glycine soja), named GsP5CS.