摘要
采用溶液培养试验,以抗寒性不同的两个小麦品种:临麦2号(高抗)和扬麦158号(低抗)为材料,研究短期低温胁迫下,加硅处理(Si 1.0 mmol/L)对小麦叶片光合作用生理参数(净光合速率、气孔导度、蒸腾速率、细胞间隙CO_2浓度和水分利用效率)及其主要酶RuBPCase和PEPCase的影响。结果表明,在短期低温胁迫下,加硅处理显著提高了小麦叶片的净光合速率、气孔导度和水分利用效率。短期低温胁迫下,两小麦品种叶片RuBPCase活性显著降低,低抗品种降低幅度更大;但加硅处理后,低抗品种RuBPCase活性显著比不加硅处理高,且与无低温处理的对照没有显著差异。硅对低抗品种扬麦158缓解低温胁迫的效果要明显高于高抗品种临麦2号。硅能显著提高低温胁迫下小麦净光合速率与硅提高小麦叶片RuBPCase活性密切相关。短期低温胁迫使小麦PEPCase活力升高,加硅处理可以抑制低抗品种中PEP羧化酶的升高,但PEPCase活力在低温胁迫条件下上升的机理有待于进一步研究。
A hydroponic experiment was performed to investigate the effects of silicon （Si） on the changes in photosynthetic parameters （Pn, Gs, Tr, Ci and WUE） and the main photosynthesis-related enzymes （RuBPCase and PEPCase） in two contrasting winter wheat cultivars, Linmai 2 （cold-resistant） and Yangmai 158 （cold-susceptible）, under shortterm cold stress. Wheat seedlings were treated with Si at 0 or 1.0 mmol/L for 3 weeks and then subjected to cold stress. The results indicated that the net photosynthetic rate （Pn）, stomatal conductance （Gs） and water utility efficiency （WUE） were significantly increased under short-term cold stress （5 h） by exogenous Si. The RuBPCase activity was significantly decreased in the seedlings of both eultivars treated with cold stress, especially in the cold-susceptible eultivar. The RuBPCase activity of the cold-susceptible cultivar subjected to cold-stress was higher in the treatment with Si than in the treatment without Si, but did not differ significantly from that of control treatment （CK, without cold stress）. The effect of Si on mitigating cold stress was better in the cold-susceptible cultivar than in the cold-resistant cultivar. The Sienhancement of the net photosynthetic rate （Pn） in wheat was closely related to Si-enhanced RuBPCase activity in wheat leaves. However, the PEPCase activity was raised under the short-term cold stress, which could be inhibited significantly by exogenous Si in the cold-susceptible cultivar. However, further investigation is needed to explore the underlying mechanisms for Si-stimulated PEPCase activity under cold stress.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2009年第3期544-550,共7页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金(30471030)
北京市自然科学基金(6052023)资助
