Plant genomes encode hundreds of proteases, which represent dozens of unrelated families. The biological role of these proteases is mostly unknown, but mutant alleles, gene silencing, and overexpression studies have provided phenotypes for a growing number of proteases. The aim of this review is to show the diversity of the processes that are regulated by proteases, and to summarize the current knowledge of the underlying molecular mechanisms. The emerging picture is that plant proteases are key regulators of a striking variety of biological processes, including meiosis, gametophyte survival, embryogenesis, seed coat formation, cuticle deposition, epidermal cell fate, stomata development, chloroplast biogenesis, and local and systemic defense responses. The functional diversity correlates with the molecular data: Proteases are specifically expressed in time and space and accumulate in different subcellular compartments. Their substrates and activation mechanisms are elusive, however, and represent a challenging topic for further research.

中文翻译：

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植物蛋白酶：从表型到分子机制

植物基因组编码数百种蛋白酶，代表数十个不相关的家族。这些蛋白酶的生物学作用大多未知，但突变等位基因、基因沉默和过表达研究为越来越多的蛋白酶提供了表型。本综述的目的是展示蛋白酶调控过程的多样性，并总结当前对潜在分子机制的了解。新出现的情况是植物蛋白酶是多种生物过程的关键调节剂，包括减数分裂、配子体存活、胚胎发生、种皮形成、角质层沉积、表皮细胞命运、气孔发育、叶绿体生物发生以及局部和全身防御反应。功能多样性与分子数据相关：蛋白酶在时间和空间中特异性表达，并在不同的亚细胞区室中积累。然而，它们的底物和激活机制是难以捉摸的，并且是进一步研究的一个具有挑战性的课题。