National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, PR China.
Plant Cell Physiol. 2011 Jun;52(6):1055-67. doi: 10.1093/pcp/pcr057. Epub 2011 May 16.
Wild species often show more tolerance to environmental stress factors than their cultivated counterparts. An early responsive-to-dehydration gene was cloned from a drought- and salt-tolerant wild tomato Solanum pennellii (SpERD15). SpERD15 transcript accumulated differentially in different organs, and was remarkably induced by dehydration, salinity, cold and treatment with plant growth regulators. The protein encoded by SpERD15 was predominantly localized in the nucleus. Interestingly, we found that the majority of the transgenic tobacco plants were co-suppressed along with the overexpressing line. Overexpressing plants manifested stress tolerance accompanied by the accumulation of more soluble sugars and proline, and limited lipid peroxidation compared with co-suppression lines, which were more sensitive than the wild type. The differential contents of these compatible solutes in different transgenic lines were related to the changes in the expression of the genes involved in the production of some important osmolytes (P5CS and Sucrose synthase). Reduced lipid peroxidation over a broad range of stress factors was in agreement with increased expression of stress-responsive genes (ADH and GAPDH). Overexpression of SpERD15 increased the efficiency of PSII (F(v)/F(m)) in transgenic tobacco plants by maintaining PSII quinone acceptors in a partially oxidized form. The results show that SpERD15 augments stress tolerance by enhancing the efficiency of PSII through the protection of cellular membranes, as conferred by the accumulation of compatible solutes and limited lipid peroxidation.
野生种通常比其栽培种更能耐受环境胁迫因子。从耐旱耐盐野生番茄 Solanum pennellii（SpERD15）中克隆出一个早期响应脱水基因。SpERD15 转录物在不同器官中差异积累，并显著受脱水、盐度、冷和植物生长调节剂处理诱导。SpERD15 编码的蛋白质主要定位于核内。有趣的是，我们发现大多数转基因烟草植物与过表达系一起被共抑制。与共抑制系相比，过表达植株表现出对胁迫的耐受性，伴随着更多可溶性糖和脯氨酸的积累，以及脂质过氧化的限制，而过表达系比野生型更敏感。不同转基因系中这些相容性溶质的差异含量与参与一些重要渗透物质（P5CS 和蔗糖合酶）产生的基因表达变化有关。在广泛的胁迫因子范围内，脂质过氧化的减少与应激响应基因（ADH 和 GAPDH）的表达增加一致。SpERD15 的过表达通过将 PSII 醌受体保持在部分氧化形式，提高了转基因烟草植株 PSII 的效率（F(v)/F(m)）。结果表明，SpERD15 通过积累相容性溶质和限制脂质过氧化来保护细胞膜，从而提高 PSII 的效率，增强了胁迫耐受性。
