Zhang Yi, Zhang Li, Hu Xiao-Hui
College of Horticulture, Northwest Agricultural & Forest University, Yangling, 712100, China.
College of Horticulture, Shanxi Agricultural University, Taigu, 030801, China.
Bot Stud. 2014 Dec;55(1):58. doi: 10.1186/s40529-014-0058-2. Epub 2014 Aug 1.
Tomato is one of the most popular vegetables, and middle tolerance for salt stress. Spermidine (Spd) has an important role in plant defense mechanisms against abiotic stress; however, relatively few data are available regarding Spd in responses of tomato to saline-alkaline stress. The effect of 0.25 mmol/L Spd on some physiological parameters of two tomato cultivars grown in 75 mmol/L saline-alkaline solutions were studied. Two cultivars are cv. Jinpeng chaoguan which is a highly salt-tolerant ecotype and cv. Zhongza No. 9 which is more salt-sensitive ecotype.
Saline-alkaline stress upset nitrogen metabolism, induced the antioxidant enzyme activities, and accumulated much more reactive oxygen species (ROS) and osmoregulation substances in two tomato cultivars leaves. Under saline-alkaline stress condition, Spd-treated seedlings accumulated more osmoregulation substances and had greater activities of antioxidative enzymes. Exogenous Spd counteracted the stress-induced increase of contents of malondialdehyde and ammonium, glutamate dehydrogenase activity, and decreased in nitrate, nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase, glutamate oxaloacetate transaminase, and glutamate pyruvate transaminase activities. Additionally, the effect of Spd was more significantly in salt-sensitive cultivar 'Zhongza No. 9'.
Overall, exogenous spermidine can attenuate negative effects of saline-alkaline stress on tomato seedlings which effects may depend on the plant species, and even cultivars.
番茄是最受欢迎的蔬菜之一，对盐胁迫具有中等耐受性。亚精胺（Spd）在植物抵御非生物胁迫的防御机制中发挥着重要作用；然而，关于Spd在番茄对盐碱胁迫响应方面的数据相对较少。研究了0.25 mmol/L Spd对在75 mmol/L盐碱溶液中生长的两个番茄品种某些生理参数的影响。两个品种分别是高度耐盐生态型的金鹏朝冠品种和盐敏感性更强的生态型中杂9号品种。
盐碱胁迫扰乱了氮代谢，诱导了抗氧化酶活性，并在两个番茄品种叶片中积累了更多的活性氧（ROS）和渗透调节物质。在盐碱胁迫条件下，经Spd处理的幼苗积累了更多的渗透调节物质，抗氧化酶活性更高。外源Spd抵消了胁迫诱导的丙二醛和铵含量增加、谷氨酸脱氢酶活性升高，以及硝酸盐、硝酸还原酶、亚硝酸还原酶、谷氨酰胺合成酶、谷氨酸合酶、谷氨酸草酰乙酸转氨酶和谷氨酸丙酮酸转氨酶活性降低的影响。此外，Spd对盐敏感品种“中杂9号”的影响更为显著。
总体而言，外源亚精胺可减轻盐碱胁迫对番茄幼苗的负面影响，其影响可能取决于植物种类，甚至品种。
