中文摘要：

以砷超富集植物大叶井口边草（Pteris cretica var.nervosa）和非超富集植物剑叶凤尾蕨（Pteris ensiformis）为供试植物,研究2mg·L-1As（Ⅴ）胁迫下添加不同浓度吲哚乙酸（IAA）对2种植物株高、生物量、叶片砷含量、光合色素、叶绿素荧光参数、暗反应酶活性和叶绿体超微结构的影响。结果表明：添加20 mg·L-1IAA后,2种植物生物量和叶片砷含量与对照相比显著增加,且大叶井口边草叶片砷含量显著高于剑叶凤尾蕨;大叶井口边草叶片光合色素含量与对照相比均无显著差异,而剑叶凤尾蕨则显著降低。随着IAA浓度增加,大叶井口边草叶片叶绿素a/b值与对照相比无显著差异,而剑叶凤尾蕨在40 mg·L-1IAA处理时显著降低。大叶井口边草叶片最大光化学效率（Fv/Fm）、实际光化学效率（ΦPSII）和非光化学淬灭系数（q N）随IAA浓度增加与对照相比无显著差异,而剑叶凤尾蕨在20 mg·L-1IAA处理下开始显著下降;大叶井口边草叶片光化学淬灭系数（q P）在10、40 mg·L-1IAA处理时显著增加,而在剑叶凤尾蕨中则显著下降。随IAA浓度增加,剑叶凤尾蕨叶片核酮糖-1,5-二磷酸羧化酶活性与对照相比显著下降,而大叶井口边草仅在10 mg·L-1IAA处理下显著下降,在20 mg·L-1IAA处理下则显著增加,在40 mg·L-1IAA处理下与对照无显著差异。添加IAA后,剑叶凤尾蕨叶片叶绿体超微结构受害严重,而大叶井口边草在20 mg·L-1IAA处理时,叶绿体仍保持完好。因此,20 mg·L-1IAA处理对砷胁迫下大叶井口边草的生长发育具有一定的光合保护作用,可使其既保持正常生长又超量富集砷。

英文摘要：

A hydroponic experiment was conducted to investigate the stress effect of arsenic（As）on Pteris cretica var. nervosa and Pteris ensiformis in the presence of indoleacetic acid（IAA）. The growth, arsenic（As）accumulation, photosynthetic pigment content, chlorophyll fluorescence parameters, activities of two dark-reaction enzymes, and chloroplast ultrastructure of the two plants were evaluated to identify the stress effect at different IAA concentrations. The results showed that biomass and frond As concentration of the two plants were significantly increased in the presence of 20 mg·L-1IAA compared to those in the respective control. The concentration of As in P. cretica var. nervosa fronds was much higher than that in P. ensiformis fronds. The photosynthetic pigment content in P. cretica var. nervosa fronds was similar to that of the control samples, but was significantly decreased in P. ensiformis. Increasing IAA concentrations did not affect the chlorophyll a/b value of P. cretica var. nervosa, compared to the control samples. However, the chlorophyll a/b value of P. ensiformis was significantly re-duced in the presence of 40 mg·L-1IAA. The maximal photochemical efficiency of photosystem Ⅱ（Fv/Fm）, actual quantum yield（ΦPSII）,and non-photochemical quenching coefficient（q N）remained unchanged in P. cretica var. nervosa fronds with increasing IAA concentra-tions, but decreased profoundly in P. ensiformis, especially in the presence of 20 mg·L-1IAA. The photochemical quenching coefficient（q P）increased significantly in P. cretica var. nervosa but diminished significantly in P. ensiformis at 10 or 40 mg·L-1IAA. The activity of ribulose-1, 5-bisphosphate carboxylase（Ru BPC） reduced significantly in P. ensiformis fronds with increasing IAA concentration. The Ru BPC activity of P. cretica var. nervosa increased significantly at 20 mg·L-1IAA but decreased at 10 mg·L-1IAA, compared to the control.IAA addition severely damaged the ultrastructure of chloroplasts in P. ensiformis at all