γ-氨基丁酸(GABA)对盐胁迫下文冠果生理特性的影响

Effects of Physiological Regulation of γ-aminobutyric Acid on the Salt Tolerance in Xanthoceras sorbifolia Bunge

以文冠果无性系扦插苗为试材,设置1%NaCl、5 mmol·L^(-1)GABA+1%NaCl、10 mmol·L^(-1)GABA+1%NaCl、15 mmol·L^(-1)GABA+1%NaCl 4个胁迫处理,测定文冠果形态指标、根系活力、内源GABA含量、保护酶活性以及丙二醛(MDA)、超氧阴离子(O_(2)^(-))和Na^(+)含量,研究了γ-氨基丁酸(GABA)对盐胁迫下文冠果生理特性的影响,以期为文冠果植株耐盐性研究提供参考依据。结果表明:盐胁迫下,文冠果植株生长速率、植株鲜质量、叶面积、根干质量、茎干质量和叶干质量显著低于对照,而主根长度显著高于对照,10 mmol·L^(-1)以上GABA明显缓解盐胁迫下文冠果生长发育,尤其15 mmol·L^(-1)GABA处理文冠果外部形态基本恢复到对照水平;外源GABA显著抑制盐胁迫下文冠果根系Na~+积累,提高超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性,从而降低MDA的积累。综上,外源GABA显著抑制盐胁迫下文冠果根系内Na^(+)积累,提高保护酶活性和根系活力,降低根系的质膜氧化损伤,缓解盐胁迫压力。

The leaf cuttings of Xanthoceras sorbifolia Bunge were used as the test materials, the four stress treatments, 1% NaCl, 5 mmLGABA+1% NaCl,mmol·L^(-1) GABA+1% NaClnd 15 mmol·L^(-1) GABA+1% NaCl were set.Morphological indexes, root activity, endogenous GABA content, protective enzyme activity, malondialdehyde(MDA)superoxde anion (O_(2)^(-)) and Nacontents were determined.The effects of γ-aminobutyric acid(GABA) on the physiological characteristics of Xanthoceras sorbifolia Bunge under salt stress were studied, in order to provide reference for the study on the salt tolerance of Xanthoceras sorbifolia Bunge.The results showed that under salt stress, the plant growth rate, plant fresh weight, leaf area, root dry weight, stem dry weight and leaf dry weight were significantly lower than the control, while the main root length was significantly higheran the control.10 mmol·L^(-1) GABA significantly alleviated the growth and development of Xanthoceras sorbifolia Bunge under salt stress.In particular, the external morphology of Xanthocerasbifolia Bunge under 15 mmol·L^(-1) GABA treatment was basically restored to the control level.Exogenus GABA significantly inhibited Na^(+) accumulation and increased the activities of superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT) in the roots of Xanthoceras sorbifolia Bunge under salt stress, thus decreasing the accumulation of MDA.In conclusion, exoenous GABA significantly inhibited Na^(+) accumulation in roots of Xanthoceras sorbifolia Bunge under salt stress, improved protective enzyme activity and root activity, reduced plasma membrane oxidative damage of roots, and alleviated salt stress.