10月18日，Plant Physiology在线发表了由我国科学家研究发现的最新研究成果。受体类激酶在植物生长发育和防御反应中起着非常重要的作用。它们在非生物胁迫反应中的作用研究较少。

在这篇题为“An S-domain receptor-like kinase OsSIK2 confers abiotic stress tolerance and delays dark-induced leaf senescence in rice”（doi:10.1104/pp.113.224881）的论文中，来自中科院遗传所的研究人员研究发现，水稻的一个具有S-结构域的受体类激酶OsSIK2参与调控非生物胁迫反应和衰老过程。研究结果表明，对于OsSIK2 的改造和应用可能有利于水稻和其它作物的改良和稳产。

OsSIK2定位于细胞质膜，在Mn²⁺存在下具有激酶活性。OsSIK2基因主要在水稻叶片和叶鞘表达，其表达受盐、干旱、冷害和植物激素ABA的诱导。过表达OsSIK2的水稻株系同对照株系相比呈现对盐胁迫和干旱胁迫的耐性。而突变体在这些胁迫处理后出现更加敏感的症状。当把OsSIK2的胞外域删除之后，表达截短蛋白的株系呈现比表达全长蛋白的株系更高的耐盐性。上述功能的差异可能是通过激活不同的下游基因引起的。全长蛋白可增强PR类基因的表达，而截短蛋白可以促进DREB类基因的表达。OsSIK2过表达株系还出现叶片发育早及黑暗诱导的衰老延迟的表型。全长蛋白和截短蛋白激活的下游基因均受盐胁迫、干旱胁迫和黑暗处理的诱导。这些结果表明，OsSIK2可能整合胁迫信号于发育过程从而使植物在不利环境条件下进行适应性生长。

根据2013年ISI发布的JCR（Journal Citation Reports）数据，Plant Physiology最新SCI影响因子为6.555，在总计197种SCI期刊的植物学科（PLANT SCIENCES）中排名第8位。在过去的12年间，该刊物影响因子处于5.105至6.555之间，并呈逐年稳步上升趋势。

论文摘要：

Receptor-like kinases (RLKs) play important roles in plant development and defense responses; however, their functions in other processes remain unclear. Here, we report that OsSIK2, an S-domain RLK from rice, is involved in abiotic stress and senescence process. OsSIK2 is a plasma membrane-localized protein with kinase activity in the present of Mn2+. OsSIK2 is expressed mainly in rice leaf and sheath, and can be induced by NaCl, drought, cold, dark and ABA treatment. Transgenic plants overexpressing OsSIK2 and mutant sik2 exhibit enhanced and reduced tolerance to salt and drought stress respectively compared to the controls. Interestingly, a truncated version of OsSIK2 without most of extracellular region confers higher salt tolerance than the full-length OsSIK2, likely through activation of different sets of downstream genes. Moreover, seedlings of OsSIK2-overexpressing transgenic plants exhibit early leaf development and delayed dark-induced senescence phenotype, while mutant sik2 shows opposite phenotype. The downstream PR-related genes specifically up-regulated by full-length OsSIK2 or the DREB-like genes solely enhanced by truncated OsSIK2 are all induced by salt and dark treatments. These results indicate that OsSIK2 may integrate stress signals into developmental program for better adaptive growth under unfavorable conditions. Manipulation of OsSIK2 should facilitate improvement of production in rice and other crops.

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