乙烯抑制剂对钾缺乏棉花根系生长和侧根形成的影响（英文）

Ethylene Inhibitors Affect Root Growth and Branching in Potassium-deficient Cotton

水培条件下,通过用乙烯前体1-氨基环丙烷基羧酸(ACC)和乙烯抑制剂氨氧基乙酸(AOA)、Co2+和Ag+分别处理棉花幼苗根系和叶片,研究其对钾缺乏棉花根系伸长和侧根形成的影响,探讨钾缺乏棉花根系伸长和侧根形成与乙烯生成增加之间的关系。结果显示,钾充分营养液中,添加ACC显著抑制了棉花根系伸长和侧根形成。钾缺乏营养液中,添加ACC加重了对根系伸长和侧根发生的抑制;添加AOA和Ag+分别显著降低了根系长度和侧根数;添加Co2+显著提高了根系长度,但其高浓度显著减少了侧根数。由此可见,钾缺乏诱导乙烯释放增加或许是根系伸长受抑制的原因。钾缺乏条件下Co2+处理叶片显著增加了叶面积、根系长度和侧根数,这表明改善叶片生长可积极调节根系生长和发育。

The relationships between increased ethylene levels induced by potassium deficiency and the inhibition of root elongating and branching of cotton, were investigated by treating roots and leaves of cotton seedlings in hydroponic cultures containing ethylene precursor ACC（1-aminocyclopropane-1-carboxylic acid） and ethylene inhibitors AOA（aminooxyacetic acid）, Co2＋and Ag＋, respectively. The addition of ACC to K＋-rich culture medium simulated the effects of K deficiency on root growth and branching, and aggravated the effects of K deficiency in K＋-poor culture medium. In contrast, treatment with high concentrations of the ethylene synthesis inhibitor AOA decreased primary root length（PRL）, lateral root length（LRL）, and lateral root number（LRN） under low K conditions, and this was similar for the ethylene action inhibitor Ag＋. Treatment with Co2＋under low K conditions significantly increased LRL and, at high concentrations, PRL, but caused reduced LRN at high concentrations. Our results indicated increased ethylene levels induced by K deficiency might account for inhibition of root elongation, but not for the suppression of root branching. Leaf application of Co2＋enhanced leaf area, root growth（PRL and LRL）, and branching（LRN） of cotton seedlings grown under low K condition, though the effects of different Co2＋concentrations were not significant. These findings suggest that improving leaf growth might positively regulate root morphology.