5-氨基乙酰丙酸对喜树幼苗盐害缓解的生理机制研究

Study on Physiological Mechanism of Alleviating Effect of 5-Aminolevulinic Acid on Camptotheca acuminata Seedlings under Salt Stress

为明确5-氨基乙酰丙酸(ALA)的生理生化机理,研究了ALA对喜树幼苗盐害的缓解效应。结果表明,80 mg L^(–1)的ALA对喜树幼苗盐胁迫的缓解效果更佳。80mgL^(–1)的ALA处理提升了盐胁迫下喜树幼苗的抗氧化能力,显著增加了幼苗叶片的氮素含量和叶绿素含量,缓解了盐胁迫对PSⅡ的破坏,提高了光合碳同化能力,从而促进幼苗生长。盐胁迫下喜树幼苗叶片的过氧化物酶(POD)活性和叶绿素含量并未随ALA浓度增加而升高。这为喜树的抗盐栽培提供了理论依据。

To clarify the physiological and biochemical mechanism of 5-aminolevulinic acid(ALA), the alleviating effect of ALA on Camptotheca acuminata seedlings under salt stress were studied. The results showed that the alleviating effect on C. acuminata seedlings under salt stress was the best treated with 80 mg L–1 ALA.Treated with 80 mg L–1 ALA spraying leaves of C. acuminata under salt stress, the antioxidant capacity was enhanced, the nitrogen and chlorophyll contents increased significantly, the damage of PS II under salt stress was relieved, which Fv/Fm was 24.35% higher than that of control, and carbon-assimilation capacity increased, Pn was 45.38% higher than that of control, so that the growth of seedlings under salt stress was promoted. The peroxidase(POD) activity and chlorophyll content of C. acuminata seedlings did not increase with increment of ALA concentration. Therefore, these would provide the theoretical basis for salt cultivation of C. acuminata.