外源5—氨基乙酰丙酸对盐胁迫下栀子幼苗生理特性的影响

采用水培方式,设置150 mmol/L Na Cl和不同质量浓度(0、25、50、100和200 mg/L)ALA溶液进行组合处理栀子幼苗,以蒸馏水处理为对照,测定不同处理下栀子叶片的光合色素、相对含水量,相对电导率、丙二醛、游离脯氨酸、可溶性糖、可溶性蛋白的量以及保护酶系统中的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性。结果表明:150 mmol/L Na Cl溶液处理下的栀子幼苗叶片中相对含水量、光合色素质量分数、可溶性蛋白质量分数以及保护酶系统SOD、POD、CAT活性显著下降,经过一定质量浓度ALA的处理,各生理指标以不同程度地提高,且ALA在25~50 mg/L处理下数值达到最大;同时在一定质量浓度ALA处理下,降低了电导率、丙二醛质量摩尔浓度,且脯氨酸、可溶性糖质量分数显著增加,提高栀子幼苗渗透调节能力。研究结果显示盐胁迫显著抑制栀子幼苗生长,ALA在25~50 mg/L时能够有效缓解盐胁迫对栀子幼苗造成的生理伤害,提高其抗盐性,而ALA在100~200 mg/L处理则有可能加剧盐胁迫。

Effect of Exogenous 5-aminolevulinic Acid on Physiological Characteristics of Gardenia jasminoides Seedlings un-der Salt Stress

By water culture, G.jasminoides seedlings living in the circumstance were cultured with 150 mmol/L NaCl and differ-ent concentrations ( 0, 25, 50, 100 and 200 mg/L) ALA, and we used water as control to study the physiological charac-teristics of G.jasminoides.We measured several physiological indexes of G.jasminoides seedlings under different treatments including photosynthetic pigment, relative water content, relative electric conductivity, malondialdehyde( MDA) , free pro-line(Pro), soluble sugar, soluble protein, superoxide(SOD), peroxidase(POD) and catalase(CAT).The relative water content, photosynthetic pigment content, soluble protein content, superoxide ( SOD), peroxidase ( POD) and catalase ( CAT) of G.jasminoides seedlings under 150 mmol/L NaCl decreased significantly, but appropriate concentration ALA could improve those physiological indexes, especially their value with 25-50 mg/L ALA reached the maximum, and re-duced their relative electric conductivity and malondialdehyde( MDA) .In addition, appropriate concentration ALA also in-creased free proline( Pro) and soluble sugar content, so that improved their osmotic regulation ability.Salt stress signifi-cantly inhibited the seedling growth of G.jasminoides seedlings.ALA with concentration of 25-50 mg/L could significantly alleviate the physiological damages to the seedlings of G.jasminoides under salt stress, and promote the salt resistance of the seedlings, while 100-200 mg/L ALA could exacerbate the salt stress.