盐胁迫对苗期向日葵内源激素含量的影响

对水培20 d的苗期向日葵进行浓度为0、50、100 mmol·L-1以及时间为10、20、30 h的盐胁迫处理,运用酶联免疫吸附法(ELISA)分别测定了各组向日葵的根部、茎秆和叶片中内源激素的浓度变化。结果表明:随着盐浓度的增加以及胁迫时间的延长,向日葵根、茎、叶中四种激素呈现不同的变化趋势。IAA,ABA和ZR三种激素总体表现为先增后降的趋势,盐浓度越大,植物激素上升或下降的幅度越大,变化速度也越快。GA没有显著变化且波动在±2.0 ng·g-1范围内。而根、茎、叶中IAA/ABA,GA/ABA,(ZR+IAA+GA)/ABA的比值总体呈下降趋势,表明了盐胁迫对生长的抑制。盐胁迫下向日葵叶片和茎秆中这几种激素的变化更为明显,而根部的变化则较为缓慢。

Effects of salt stress on endogenous hormone contents in sunflower seedlings

The hydroponic cultured sunflower seedlings after 20d was treated in 0, 50, and 100 mmol·L^-1 salt solution for 0, 10, 20, and 30 h as salt stress treatments. The concentrations of endogenous hormones in roots, stems, and leaves of sunflower seedlings were determined by enzyme-linked immunosorbent assay (ELISA). The results indicated that with increasing salt concentrations and stress time, the four hormones in root, stem, and leaves of the seedlings showed inconsistent trends. The content of IAA, ABA, and ZR increased first and then decreased. The greater the salt concentration, the greater the amplitude of the increase or decrease in the hormone contents and the faster the change rate in the hormones content. GA did not change significant and fluctuated within the ±2.0 ng·g^-1 range during salt stress treatment. The ratio of IAA/ABA, GA/ABA, and (ZR+IAA+GA) /ABA in roots, stems, and leaves of sunflowers showed an overall downward trend, indicating salt stress inhibited sunflower growth. It is shown that under salt stress, the changes in concentrations of these hormones in leaves and stems of sunflower seedlings were greater than that in roots.