外源钙及钙抑制剂对番茄耐弱光特性的调控作用

Regulations of Calcium and Calcium Inhibitors on the Low Light Tolerance in Tomato

为探讨外源钙对番茄弱光胁迫生育障碍的可能调控作用,以栽培型番茄（Lycopersicon esculentum Mill）品系W为材料,采用外源钙和钙通道抑制剂LaCl3及钙离子螯合剂EGTA处理50%自然光强（实测光通量密度为475.2~616.5μmol.m-2.s-1）条件下生长的番茄植株,通过各项相关指标的测定研究其对弱光下番茄生长发育、光合作用、防御酶活性等的影响。结果表明,遮光50%的弱光条件下,27 mmol.L-1CaCl2处理的番茄茎粗增加,植株整体生长健壮,有效抑制植株徒长。外源钙可通过有效防护胁迫所致的氧化损伤,维持较高的防御酶活性及可溶性蛋白含量来抑制脂质过氧化,从而使番茄叶片在弱光胁迫下维持较高的光合能力,有利于物质积累;而钙通道抑制剂和钙离子螯合剂的作用则与之相反。由此可见,外源钙可在一定程度上弥补弱光胁迫对番茄植株造成的伤害,使植株能够维持较正常的生理活动,稳定细胞膜结构,保护光合机构,提高防御酶系统活性,降低膜质过氧化程度,对番茄植株的弱光耐性具有正调控作用。

In order to investigate the regulating mechanism of calcium on tomato low light tolerance,one tomato（Lycopersicon esculentum Mill） strain W were used to study the changes of plant height,stem diameter,photosynthesis and protective enzymes activities,after the tomato were treated by calcium,calcium channel inhibitor LaCl3 and Ca2＋ chelator（EGTA） under the 50% nature light intensity.The results showed that Ca2＋ treatment could inhibit the phenomenon of spindly growth which was caused by low light stress to a certain extent,decrease MDA content,increase the activities of SOD,CAT,and POD,promote the content of soluble protein in the leaves of tomato under low light stress（475.2-616.5 μmol·m-2·s-1） which is covered 50% nature light,close to or even reach the control level under 100% nature light intensity.But the effects of calcium channel inhibitor and Ca2＋ chelator were opposite.These results indicated that the effects of calcium on the growth and development of plant,photosynthesis,activities of protective enzymes and the content of soluble protein in the leaves of tomato under low light stress was a positive regulation,this maybe one of the important reasons for that calcium could increased low light tolerance of tomato,prevented low light damage to the plant in a certain extent.