子叶磷在白羽扇豆缺磷适应性反应中的作用

摘要

实验用液体培养的方法，对比分析了在不同供磷条件下，白羽扇豆子叶中的磷对植物生长发育的影响，以及对排根和根尖中有机酸积累和分泌的作用。结果表明，子叶中的磷能使白羽扇豆在完全缺磷23 d的环境中，不仅没有使干物质的积累减少，反而使干物质的积累略有增加。相反，如果没有子叶磷的供给，则使白羽扇豆在缺磷环境中产生强烈的抗胁迫反应，表现在干物质的积累明显下降，根系能产生大量的排根，排根能积累和分泌大量的柠檬酸，而根尖能积累和分泌苹果酸。在整个缺磷反应过程中，根尖中苹果酸的积累和分泌要早于排根中柠檬酸的积累和分泌%In present study,we in investigated 1 what role does the cotyledons play in the growing and developing of phosphorus deficient white lupin?2 the effect of phosphorus in the cotyledons on the accumulation and exudation of organic acids in/from root tips and proteoid roots of P-deficient white lupin.The result shown:the growth and development of P-deficient white lupine with cotyledons were not inhibited compared with the P-sufficient white lupine.On the contray,when the cotyledons were removed,the responses of P-deficient white lupine got more intensive.The accumulation of dry matter reduced and more proteoid roots were induced.The accumulation and excretion of citric acid in/from proteoid roots were enhanced,in the mean time,the root tips could accumulate and secrete malic acid.The malic acid accumulated and secreted in/from root tips was earlier than citric acid accumulated and secreted in/from proteoid roots.