Development of regulating technique of amino acid metabolism and fruit quality by salt/drought stress treatment on tomato, a model Solanaceae crop

众所周知，对番茄根部进行轻度盐胁迫处理可提高番茄果实中的蔗糖含量。钙离子和蛋白质磷酸化在盐胁迫信号转导和获得耐盐性中起着重要作用。近年来对植物逆境信号转导的研究表明，植物代表性SNF 1相关激酶可分为3个亚类：SnRK 1参与营养信号转导，SnRK 2参与光合调节和气孔关闭相关信号转导，SnRK 2/CIPK调节离子转运机制。为了检查SnRK 2和CIPK是否在生殖器官特异性应激信号传导中起作用，通过用抗-SlSnRK 2C抗体的免疫印迹和用一组SnRK 2 CIPK同源物特异性引物的半定量RT-PCR来分析SlSnRK 2C和钙调磷酸酶B样分子（CBL）相互作用蛋白激酶（CIPK）的表达谱。SlCIPK 2被鉴定为番茄Micro-Tom中花器官特异性的CIPK，而SlSnRK 2C在幼果中被特异性地检测到。此外，抗CIPK特异性抗体在花中，特别是在雄蕊中以显著水平与CIPK相关多肽、与花特异性CIPK的重组蛋白SlCIPK 2交叉反应。针对番茄SOS 3同源物制备了一种特异性抗体，该同源物可能与番茄的耐盐性有关。盐胁迫下，番茄叶片中SlSOS 3的免疫检测信号增强。目前的数据表明，SlSnRK 2C和SlCIPK 2分别参与果实和花，和SOS 3可能调节盐胁迫信号功能在叶中，而不是在花中。

It is well known that a mild salt stress treatment on tomato roots enhances sucrose content in tomato fruit. Calcium and protein phosphorylation have appeared to play important roles in salt stress signaling and aquired salt tolerance. Recent studies of plant stress signaling revealed that plant representative SNF1-related kinases are classified into 3 subgroups, SnRK1 involved in nutrient signaling, SnRK2 functioning in osmoregulation- and stomatal-closing-related signalings and SnRK2/CIPK regulating ion transport mechanism. To examine whether SnRK2 and CIPK functions in reproductive organ-specific stress signaling, expression profiles of SlSnRK2C and Calcineurin B-Like molecule (CBL) Interacting Protein Kinases (CIPK) were analyzed by immunoblot with anti-SlSnRK2C antibody and semi-quantitative RT-PCR with a set of SnRK2 CIPK homolog specific primers. SlCIPK2 has been identified as a floral organ-specific CIPK in tomato Micro-Tom while SlSnRK2C was detected specifically in young fruit. Furthermore, an anti-CIPK specific antibody cross-reacted to a CIPK-related polypeptide at a significant level in flower particularly, in stamen, to the recombinant protein of the flower specific CIPK, SlCIPK2. A specific antibody was raised against tomato SOS3 homolog which is possibly involved in salt tolerance. Immuno-detected signal of SlSOS3 in leaf increased when tomato plant was subjected to salt stress. The present data suggests that SlSnRK2C and SlCIPK2 are involved in fruit and flower, respectively and that SOS3 possibly regulating salt stress signaling function in leaf but not in flower.