Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, DAPO, Metro Manila, Philippines.
Physiol Plant. 2012 May;145(1):165-79. doi: 10.1111/j.1399-3054.2012.01573.x. Epub 2012 Feb 23.
Integral subcellular and cellular functions ranging from gene expression, protein targeting and nutrient supply to cell differentiation and cell death require proteases. Plants have unique organelles such as chloroplasts composed of unique proteins that carry out the unique process of photosynthesis. Hence, along with proteases common across kingdoms, plants contain unique proteases. Improved knowledge on proteases can lead to a better understanding of plant development, differentiation and death. Because of their importance in multiple processes, plant proteases are actively studied. However, root proteases specifically are not as well studied. The associated rhizosphere, organic matter and/or inorganic matter make roots a difficult system. Yet recent research conclusively demonstrated the occurrence of endocytosis of proteins, peptides and even microbes by root cells, which, hitherto known for specialized pathogenesis or symbiosis, was unsuspected for nutrient uptake. These results reinforced the importance of root proteases in endocytosis or root exudate-mediated nutrient uptake. Rhizoplane, rhizosphere or in planta protease action on proteins, peptides and microbes generates sources of nitrogen, especially during abiotic stresses such as drought. This article highlights the recent research on root proteases for nitrogen uptake and the connection of the two to drought-tolerance mechanisms. Drought-induced proteases in rice roots, as known from rice expression databases, are discussed for future research on certain M50, Deg, FtsH, AMSH and deubiquitination proteases. The recent emphasis on linking drought and plant hydraulics to nutrient metabolism is illustrated and connected to the value of a systematic study of root proteases in crop improvement.
从基因表达、蛋白质靶向和营养供应到细胞分化和细胞死亡等完整的亚细胞和细胞功能都需要蛋白酶。植物具有独特的细胞器，如由执行光合作用独特过程的独特蛋白质组成的叶绿体。因此，除了在各个领域普遍存在的蛋白酶外，植物还含有独特的蛋白酶。对蛋白酶的深入了解可以促进对植物发育、分化和死亡的更好理解。由于它们在多个过程中的重要性，植物蛋白酶受到了积极的研究。然而，具体的根蛋白酶并没有得到很好的研究。相关的根际、有机物和/或无机物使根成为一个困难的系统。然而，最近的研究确凿地证明了根细胞内吞蛋白质、肽甚至微生物的发生，这对于专门的发病机制或共生是已知的，但对于养分吸收是未知的。这些结果强化了根蛋白酶在内吞作用或根分泌物介导的养分吸收中的重要性。根面、根际或植物体内蛋白酶对蛋白质、肽和微生物的作用产生氮源，尤其是在非生物胁迫如干旱期间。本文重点介绍了根蛋白酶在氮吸收方面的最新研究以及两者与耐旱机制的联系。根据水稻表达数据库可知，水稻根中干旱诱导的蛋白酶被讨论用于某些 M50、Deg、FtsH、AMS 和去泛素化蛋白酶的未来研究。最近强调将干旱与植物水力学联系起来与养分代谢的重点，并与系统研究根蛋白酶在作物改良中的价值联系起来。
