Department of Genetics, University of Stellenbosch, Stellenbosch, 7601, South Africa.
Department of Plant and Soil Sciences, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0002, South Africa.
Plant Cell Environ. 2017 Sep;40(9):1679-1690. doi: 10.1111/pce.12998.
Bread wheat (Triticum aestivum L.) provides about 19% of global dietary energy. Environmental stress, such as drought, affects wheat growth causing premature plant senescence and ultimately plant death. A plant response to drought is an increase in protease-mediated proteolysis with rapid degradation of proteins required for metabolic processes. Among the plant proteases that are increased in their activity following stress, cysteine proteases are the best characterized. Very little is known about particular wheat cysteine protease sequences, their expression and also localization. The current knowledge on wheat cysteine proteases belonging to the five clans (CA, CD, CE, CF and CP) is outlined, in particular their expression and possible function under drought. The first successes in establishing an annotated wheat genome database are further highlighted which has allowed more detailed mining of cysteine proteases. We also share our thoughts on future research directions considering the growing availability of genomic resources of this very important food crop. Finally, we also outline future application of developed knowledge in transgenic wheat plants for environmental stress protection and also as senescence markers to monitor wheat growth under environmental stress conditions.
面包小麦（Triticum aestivum L.）提供了全球约 19%的饮食能量。环境胁迫，如干旱，会影响小麦的生长，导致植物提前衰老，最终导致植物死亡。植物对干旱的反应是蛋白酶介导的蛋白水解增加，导致代谢过程所需的蛋白质迅速降解。在应激后活性增加的植物蛋白酶中，半胱氨酸蛋白酶的特征最为明显。关于特定的小麦半胱氨酸蛋白酶序列、它们的表达和定位，人们知之甚少。本文概述了属于五个族（CA、CD、CE、CF 和 CP）的小麦半胱氨酸蛋白酶的现有知识，特别是它们在干旱下的表达和可能的功能。进一步强调了在建立注释小麦基因组数据库方面取得的初步成功，这使得对半胱氨酸蛋白酶的更详细挖掘成为可能。我们还就未来的研究方向分享了我们的想法，考虑到这个非常重要的粮食作物的基因组资源越来越丰富。最后，我们还概述了开发的知识在用于环境胁迫保护的转基因小麦植物中的未来应用，以及作为监测小麦在环境胁迫条件下生长的衰老标记。
