Overexpression of ShCHL P in tomato improves seedling growth and increases tolerance to salt, osmotic, and oxidative stresses
Overexpression of ShCHL P in tomato improves seedling growth and increases tolerance to salt, osmotic, and oxidative stresses
复制标题
番茄中 ShCHL P 的过度表达可改善幼苗生长并提高对盐、渗透和氧化胁迫的耐受性
DOI：
10.1007/s10725-015-0054-x
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发表时间：
2015-11-01
影响因子：
4.2
通讯作者：
Chen, Jiang-Shu
中科院分区：
文献类型：
--
作者：
Liu, Hui;Liu, Jian;Chen, Jiang-Shu
香叶基香叶基还原酶(CHL-P)催化香叶基香叶基二磷酸还原为植基二磷酸，为叶绿素(Chl)和生育酚(TP)的合成提供植物酚。我们先前的研究发现，龙葵CHL-P(ShCHL-P)基因受冷胁迫的抑制。在这项研究中，我们从功能上描述了该基因在非生物胁迫耐受性方面的作用。Shchl P在叶和茎中高表达，在根中几乎不表达。此外，它的表达受到低温和高温、干旱、盐和氧化应激的抑制。过量表达ShCHL-P的转基因番茄叶片中的Chl和α-TP水平增加。相反，共抑制植物的Chl和α-TP含量降低，表现为黄化。这些结果证实了以前的发现，即Chl-P对植物Chl和TP的合成是必需的。此外，与野生型相比，ShCHL P高表达系和抑制系在正常、盐和渗透胁迫条件下分别表现出对幼苗早期生长的改善和抑制作用。令人惊讶的是，在转基因番茄中过表达和抑制ChL P都提高了对甲基紫精诱导的氧化胁迫的耐受性。这些结果表明，番茄Chl-P通过调节Chl和TP的合成，在响应非生物胁迫中起着重要作用。Chl-P基因可能是番茄非生物胁迫下植物生长遗传改良的候选基因。
Geranylgeranyl reductase (CHL P) catalyzes the reduction of geranylgeranyl diphosphate to phytyl diphosphate and provides phytol for both chlorophyll (Chl) and tocopherol (TP) synthesis. Our previous study has found that the Solanum habrochaitesCHL P (ShCHL P) gene was repressed by cold stress. In this study, we functionally characterized this gene with respect to abiotic stress tolerance. ShCHL P is expressed highly in leaves and stems, and barely in roots. Also, its expression was suppressed by low and high temperatures, drought, salt, and oxidative stresses. Transgenic tomato plants overexpressing ShCHL P showed increased levels of Chl and α-TP in leaves. In contrast, Chl and α-TP contents were reduced in the co-suppression plants, which exhibited chlorosis. These results confirmed the previous findings that CHL P is essential for Chl and TP synthesis in plants. Moreover, the ShCHL P overexpression and suppression lines showed improved and inhibited early seedling growth under normal, salt, and osmotic stress conditions, respectively, as compared with the wild type. Surprisingly, both overexpression and suppression of CHL P in transgenic tomato enhanced tolerance to methyl viologen-induced oxidative stress. These results indicate that tomato CHL P plays an important role in response to abiotic stress through regulation of Chl and TP synthesis. CHL P might be a good candidate gene for genetic improvement of plant growth under abiotic stress conditions in tomato.