生长素萘乙酸对甘蔗锰毒的调控

Regulation of NAA on sugarcane manganese toxicity

为探究萘乙酸对锰毒胁迫下的甘蔗锰铁含量、运输及分布的影响及生长素极性运输抑制剂对植株锰含量的影响,以桂糖32号为材料,进行水培试验,结果表明:10、50、100、500 nmol/L萘乙酸处理后,随着萘乙酸浓度的增加,甘蔗根系锰含量随之显著降低8.59%～36.11%,100 nmol/L萘乙酸处理后完全展开叶锰含量显著减少17.67%～25.56%,完全展开叶叶鞘中共质体及其残渣的锰含量显著减少40.00%和31.82%,但根表锰膜/根组织锰含量比、茎基部伤流液中Mn浓度、叶片质外体、共质体及残渣中锰含量、根系生长及植株中铁和亚铁含量萘乙酸处理与空白对照间差异不显著。生长素输出抑制剂三碘苯甲酸或萘基邻氨甲酰苯甲酸(1 000 nmol/L)处理后,植株幼叶锰含量(76.64、73.45 mg/kg)显著高于对照(38.26mg/kg)。说明生长素可能参与调控甘蔗对锰的吸收缓解锰毒。

The research on effects of naphthaleneacetic acid on iron-manganese content,transport and distribution and the influence of auxin polar transport inhibitor on Mn content under manganese toxicity in sugarcane（Saccharum officinarum L） was designed with hydroponic experiments,treated on Guitang 32. The results showed Mn content in roots significantly decreased by 8.59%-36.11% with the increase of NAA concentration treated at 10,50,100,and 500 nmol/L. The Mn content in the fully expanded leaves also significantly reduced by17.67%-25.56% after treatment with naphthaleneacetic acid,and the Mn contents in symplast and its residue of sheath decreased by 40.00% and 31.82%;but the ratio of Mn content in the manganese plaque and root tissue,Mn concentration in the bleeding fluid from stem base,Mn content in leaves apoplast,symplast and residue,root growth and iron and ferrous iron content in the plant treated with naphthaleneacetic acid were no significant difference compared with the control treatment. On the other hand,after treatment with the auxin output inhibitor triiodobenzoic acid or naphthyl phthalamic acid（ 1 000 nmol/L）,the Mn content of the unexpanded leaves（ 76.64,73.45 mg/kg）significantly higher than the control（ 38.26 mg/kg）. These results suggested that auxin might participate in the regulation of sugarcane on Mn absorption to alleviate Mn toxicity rather than transportation and distribution.