Overexpression of a vacuolar H+-pyrophosphatase and a B subunit of H+-ATPase cloned from the halophyte Halostachys caspica improves salt tolerance in Arabidopsis thaliana
Overexpression of a vacuolar H+-pyrophosphatase and a B subunit of H+-ATPase cloned from the halophyte Halostachys caspica improves salt tolerance in Arabidopsis thaliana
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DOI：
10.1007/s11240-011-0013-9
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发表时间：
2012-01-01
影响因子：
3
通讯作者：
Zhang, Fu-chun
中科院分区：
文献类型：
--
作者：
Hu, You-zhen;Zeng, You-ling;Zhang, Fu-chun
为了避免Na+毒害的影响，植物已经发展出将Na+隔离在液泡中的机制。这种隔离过程是由液泡Na+/H+逆向转运蛋白催化的，跨膜电化学势最初由液泡膜H+-ATPase和H+-焦磷酸酶(H+-PPase)建立。在本研究中，我们从广布于中亚的耐盐多汁灌木Halostachys caspica中克隆了HcVP1和HcVHA-B，分别编码液泡型H+-PPase和H+-ATPase的B亚基。HcVP1全长2,295个碱基，包含一个764个氨基酸的开放阅读框(ORF)；HcVHA-B全长1,467个碱基，开放阅读框(ORF)为488个氨基酸。半定量PCR结果表明，盐胁迫诱导了这两个基因在caspica中的转录。此外，与野生型植株相比，异源表达HcVP1或HcVHA-B的转基因拟南芥的种子萌发和植株生长都得到了提高。具体地说，转基因拟南芥叶片中Na+含量高于野生型植株。这些结果表明，液泡H+-PPase和H+-ATPase B亚基的过表达可能通过增加液泡中Na+的积累来提高转基因拟南芥的耐盐性。
To avoid the effects of Na+ toxicity, plants have developed mechanisms to sequester Na+ in vacuoles. This sequestration process is catalyzed by a vacuolar Na+/H+ antiporter, with the transmembrane electrochemical potential initially established by the tonoplast H+-ATPase and H+-pyrophosphatase (H+-PPase). In this study, we cloned HcVP1 and HcVHA-B encoding a vacuolar H+-PPase and a B subunit of H+-ATPase, respectively, from Halostachys caspica, a succulent shrub that is highly salt-tolerant and widely distributed in Central Asia. The cDNA of HcVP1 is 2,295 bp and contains an open reading frame (ORF) of 764 amino acids and the HcVHA-B cDNA is 1,467 bp with an ORF of 488 amino acids. Semi-quantitative PCR revealed that transcription of both genes in H. caspica is induced by salt stress. Additionally, increased seed germination and improved plant growth were observed in transgenic Arabidopsis thaliana plants heterologously expressing HcVP1 or HcVHA-B, relative to wild-type plants when grown in the presence of NaCl. Specifically, Na+ content in leaves of transgenic Arabidopsis plants was higher than in wild-type leaves. These results demonstrate that overexpression of a vacuolar H+-PPase and a B subunit of H+-ATPase from H. caspica may enhance salt tolerance in transgenic Arabidopsis through increased accumulation of Na+ in vacuoles.