A class I cytosolic HSP20 of rice enhances heat and salt tolerance in different organisms
A class I cytosolic HSP20 of rice enhances heat and salt tolerance in different organisms
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水稻的 I 类胞质 HSP20 增强不同生物体的耐热性和耐盐性
DOI：
10.1038/s41598-020-58395-8
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发表时间：
2020-01-28
影响因子：
4.6
通讯作者：
Zhang, Heng-Mu
中科院分区：
文献类型：
--
作者：
Guo, Liu-Ming;Li, Jing;Zhang, Heng-Mu
小分子热休克蛋白(SHSPs)被认为是一种伴侣蛋白，当生物体受到各种生物和非生物胁迫时，保护其靶标免受变性和聚集。我们以前报道了水稻(OsHSP20)的SHSP，它在细胞质内同源二聚并形成颗粒，但其功能尚不清楚。我们现在发现，OsHSP20的转录本在热激和高盐条件下显着上调，但不受干旱的影响。纯化了一个重组蛋白，并在体外抑制了线粒体苹果酸脱氢酶(MDH)的热聚集，这种分子伴侣活性表明OsHSP20可能参与了抗逆性。与对照相比，异源表达OsHSP20的巴斯德毕赤酵母细胞对高温和盐胁迫的耐受性增强。高表达OsHSP20的转基因水稻植株在高温和盐处理下比对照植株的根更长，发芽率更高。利用其截短突变体进行的一系列分析表明，其N末端加上ACD结构域对其同源二聚化、体外分子伴侣活性和体内抗逆性至关重要。这些结果支持了OsHSP20可能通过其分子伴侣活性在不同生物中赋予耐热性和耐盐性的观点，也为HSP20介导的抗逆性提供了更全面的表征。萨瓦尔。
Small heat shock proteins (sHSPs) have been thought to function as chaperones, protecting their targets from denaturation and aggregation when organisms are subjected to various biotic and abiotic stresses. We previously reported an sHSP fromOryza sativa(OsHSP20) that homodimerizes and forms granules within the cytoplasm but its function was unclear. We now show that OsHSP20 transcripts were significantly up-regulated by heat shock and high salinity but not by drought. A recombinant protein was purified and shown to inhibit the thermal aggregation of the mitochondrial malate dehydrogenase (MDH) enzymein vitro, and this molecular chaperone activity suggested that OsHSP20 might be involved in stress resistance. Heterologous expression of OsHSP20 inEscherichia coliorPichia pastoriscells enhanced heat and salt stress tolerance when compared with the control cultures. Transgenic rice plants constitutively overexpressing OsHSP20 and exposed to heat and salt treatments had longer roots and higher germination rates than those of control plants. A series of assays using its truncated mutants showed that its N-terminal arm plus the ACD domain was crucial for its homodimerization, molecular chaperone activityin vitro, and stress tolerancein vivo. The results supported the viewpoint that OsHSP20 could confer heat and salt tolerance by its molecular chaperone activity in different organisms and also provided a more thorough characterization of HSP20-mediated stress tolerance inO. sativa.