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增强的紫外线-B(UV-B)辐射会对植物的抗氧化系统造成破坏,而很多研究已经证明茉莉酸(JA)具有缓解某些胁迫效应的作用。为了解JA对UV-B辐射胁迫下小麦抗氧化系统影响的时间和浓度效应,本研究中小麦幼苗接受增强的UV-B辐射前分别用不同浓度JA(1mmol/L,2.5mmol/L,5mmol/L,7.5mmol/L,10mmol/L)进行预处理,然后研究其在UV-B辐射3h、6h、9h、12h、15h、18h内丙二醛(MDA),过氧化物酶(POD),过氧化氢酶(CAT),脯氨酸,紫外吸收物(黄酮类及相关酚,花青素),光合色素(叶绿素a:Chla;叶绿素b:Chlb;类胡萝卜素:Car)浓度的变化。单因素方差分析表明:UV-B辐射对各个指标的影响表现出随时间变化明显的波动,并且不同浓度的外源JA显现出不同的效应。外源JA能够缓解UV-B辐射第3小时、第12小时和第18小时所造成的脂质过氧化损伤,这与适中浓度的JA(2.5mmol/L,5mmol/L,7.5mmol/L)所诱导的黄酮及相关酚类物质、花青素以及脯氨酸含量的提高有关,而与POD和CAT无关。此外,若UV-B辐射时间小于18h,JA可通过增加光合天线系统体积的方式来减轻UV-B辐射对天线系统的破坏效应,但这种调控作用随辐射时间延长而降低。
Enhanced UV-B radiation damages the plant’s antioxidant system, and many studies have shown that jasmonic acid (JA) has the effect of relieving some stress effects. In order to understand the time and concentration effects of JA on the antioxidant system of wheat under UV-B radiation stress, wheat seedlings were treated with different concentrations of JA (1 mmol / L, 2.5 mmol / L, 5 mmol /L, 7.5mmol / L, 10mmol / L). The effects of UV-B radiation on malondialdehyde (MDA), peroxidase (POD) , Catalase (CAT), proline, UV absorbers (flavonoids and related phenols, anthocyanins), photosynthetic pigments (chlorophyll a: Chla, chlorophyll b: Chlb, carotenoid: Car) . One-way ANOVA showed that the influence of UV-B radiation on each index showed obvious fluctuation with time, and different concentrations of exogenous JA showed different effects. Exogenous JA can alleviate the lipid peroxidation damage induced by UVB radiation at the 3rd hour, the 12th hour and the 18th hour, which is consistent with the moderate JA concentration (2.5mmol / L, 5mmol / L, 7.5mmol / L) Induced flavonoids and related phenols, anthocyanins and proline content increased, and has nothing to do with POD and CAT. In addition, if UV-B irradiation time is less than 18h, JA can reduce the damage effect of UV-B radiation on the antenna system by increasing the volume of photosynthetic antenna system, but this regulation decreases with the extension of irradiation time.