Department of Botany, Yogi Vemana University, Kadapa 516 003, India.
J Plant Physiol. 2011 May 1;168(7):671-7. doi: 10.1016/j.jplph.2010.09.007. Epub 2010 Oct 29.
Plants produce an array of proteins as a part of a global response to protect the cell metabolism when they grow under environmental conditions such as drought and salinity that generate reduced water potential. The synthesis of hydrophilic proteins is a major part of the response to water deficit conditions. An increased expression of LEA proteins is thought to be one of the primary lines of defense to prevent the loss of intercellular water during adverse conditions. These LEA proteins are known to prevent aggregation of a wide range of other proteins. In this study we report the water stress induced protein aggregation and its abrogation followed by expression of group 1 and group 2 LEA proteins of water soluble proteomes in horsegram. Water stress caused an increased protein aggregation with magnitude and duration of stress in horsegram seedlings. Tissue-specific expression of LEA 1 protein decreased in the embryonic axis when compared to cotyledons in 24h stressed seedlings. We found no cross reaction of LEA 1 with proteome of 48h stressed embryonic axis and 72h stressed root and shoot samples. However, LEA 2 antibodies were cross reacted with four polypeptides with different molecular mass in shoot tissue samples and found no reaction with root proteome as evidenced from immuno-blot analysis. The role of LEA proteins in relation to protein aggregation during water stressed conditions was discussed.
当植物在干旱和盐渍等环境条件下生长时，会产生一系列蛋白质，作为细胞代谢保护的全球反应的一部分，这些环境条件会降低水势。亲水性蛋白质的合成是对水分亏缺条件反应的主要部分。LEA 蛋白表达的增加被认为是防止细胞间水分在不利条件下流失的主要防御机制之一。这些 LEA 蛋白被认为可以防止广泛的其他蛋白质的聚集。在这项研究中，我们报告了马豆在水分胁迫下诱导的蛋白质聚集及其消除，以及水溶性蛋白质组中第 1 组和第 2 组 LEA 蛋白的表达。在马豆幼苗中，水分胁迫导致蛋白质聚集增加，其程度和持续时间与胁迫有关。与 24 小时胁迫的子叶相比，LEA1 蛋白在胚胎轴中的组织特异性表达降低。我们发现，LEA1 蛋白与 48 小时胁迫的胚胎轴和 72 小时胁迫的根和茎组织样品的蛋白质组没有交叉反应。然而，LEA2 抗体与茎组织样品中的四个具有不同分子量的多肽发生交叉反应，并且从免疫印迹分析来看，与根蛋白质组没有反应。讨论了 LEA 蛋白在水分胁迫条件下与蛋白质聚集的关系。
