NARO Institute of Crop Science , Tsukuba 305-8518, Japan.
J Proteome Res. 2013 Nov 1;12(11):4785-98. doi: 10.1021/pr4002349. Epub 2013 Jul 23.
Flooding injury is one of the abiotic constraints on soybean growth. An experimental system established for evaluating flooding injury in soybean seedlings indicated that the degree of injury is dependent on seedling density in floodwater. Dissolved oxygen levels in the floodwater were decreased by the seedlings and correlated with the degree of injury. To understand the molecular mechanism responsible for the injury, proteomic alterations in soybean seedlings that correlated with severity of stress were analyzed using label-free quantitative proteomics. The analysis showed that the abundance of proteins involved in cell wall modification, such as polygalacturonase inhibitor-like and expansin-like B1-like proteins, which may be associated with the defense system, increased dependence on stress at both the protein and mRNA levels in all organs during flooding. The manner of alteration in abundance of these proteins was distinct from those of other responsive proteins. Furthermore, proteins also showing specific changes in abundance in the root tip included protein phosphatase 2A subunit-like proteins, which are possibly involved in flooding-induced root tip cell death. Additionally, decreases in abundance of cell wall synthesis-related proteins, such as cinnamyl-alcohol dehydrogenase and cellulose synthase-interactive protein-like proteins, were identified in hypocotyls of seedlings grown for 3 days after flooding, and these proteins may be associated with suppression of growth after flooding. These flooding injury-associated proteins can be defined as indicator proteins for severity of flooding stress in soybean.
水淹胁迫是影响大豆生长的非生物胁迫之一。本研究采用建立的大豆幼苗水淹胁迫模型，发现水淹胁迫程度与幼苗在水中的密度有关，且胁迫导致水中溶解氧降低。为了阐明水淹胁迫导致大豆幼苗伤害的分子机制，本研究采用无标记定量蛋白质组学方法，分析了与胁迫严重程度相关的大豆幼苗蛋白质组学变化。结果表明，与细胞壁修饰相关的蛋白，如多聚半乳糖醛酸酶抑制剂样蛋白和扩展蛋白 B1 样蛋白的丰度增加，这些蛋白可能与防御系统有关，且在水淹胁迫过程中，所有器官中的蛋白和 mRNA 水平对胁迫的依赖性增加。这些蛋白丰度变化的方式与其他响应蛋白不同。此外，在根尖中还发现了一些特定变化的蛋白，如蛋白磷酸酶 2A 亚基样蛋白，这些蛋白可能参与水淹诱导的根尖细胞死亡。此外，在水淹 3 天后的下胚轴中还鉴定到细胞壁合成相关蛋白，如肉桂醇脱氢酶和纤维素合酶互作蛋白样蛋白的丰度降低，这些蛋白可能与水淹后生长受到抑制有关。这些水淹胁迫相关蛋白可以作为鉴定大豆水淹胁迫严重程度的指标蛋白。
