渗透胁迫下钙对小麦胚芽鞘和根系生长的影响

 以精选冬小麦(Triticum aestivum L.)4185种子为试验材料，采用CaCl2、EGTA、LaCl3及Verapamil配制的溶液处理萌发24 h的小麦根系，研究其胚芽鞘及根系对渗透胁迫的不同反应。结果表明，PEG-6000（20%）诱导的渗透胁迫下，低浓度Ca2+（10-6～10-3 mol·L-1）处理小麦根系时，不同浓度处理间胚芽鞘及根系的生长无显著差异，10-2 mol·L-1的Ca2+则抑制胚芽鞘和根系的生长；EGTA（1、5、10 mmol·L-1）、LaCl3（0.5、1 mmol·L-1）和Verapamil（250、500 μmol·L-1）处理根系时，均抑制了胚芽鞘和根系的生长，这种抑制效应与提高过氧化物酶（POD）活性有密切关系。表明在渗透胁迫下，小麦对缺钙更敏感，高浓度Ca2+以及减少细胞外Ca2+和阻断Ca2+的运转，均对生长有抑制作用。

Effect of Calcium on Growth of Coleoptile and Root in Wheat Under Osmotic Stress

Under osmotic stress induced by PEG-6000 (20%), when the roots of wheat（Triticum aestivum L. cv 4185）were treated with low concentration of exogenous Ca2+ at 10-6-10-3 mol·L-1, there were no significant difference in growth of coleoptiles and roots, but the growth was inhibited by exogenous Ca2+ at 10-2 mol·L-1. The treatments for roots with EGTA (1, 5,10 mmol·L-1), LaCl3 (0.5, 1 mmol·L-1) and Verapamil (250, 500 μmol·L-1) inhibited the growth of coleoptiles and roots, which were closely related to the increase of peroxidase (POD) activity. These results showed that under osmotic stress, the wheat was more sensitive to deficiency of Ca2+. The higher exogenous Ca2+ concentration, lower extracellular Ca2+ concentration and blocking Ca2+ transfer would suppress the growth of wheat coleoptiles and roots.