外用不同浓度茉莉酸甲酯诱导的茶树挥发物的种类和时序变化

【目的】明确MeJA对茶树挥发物的诱导作用。【方法】采用顶空活体取样法对不同浓度MeJA处理后的茶苗挥发物进行抽提,并利用GC-MS对挥发物进行鉴定。【结果】不同剂量MeJA显著地影响茶树挥发物的种类组成和释放量,50μL MeJA处理可显著诱导茶树释放香叶烯、萜品油烯、罗勒烯等10种单萜类化合物,法呢烯、橙花叔醇和红没药烯等7种倍半萜类化合物,苯甲醇、苯乙腈和吲哚等5种氨基酸衍生物,以及3种未知化合物;而100μL MeJA处理仅能诱导茶树释放7种化合物。不同挥发物对MeJA处理的响应时间不同,但其释放量都具有昼高夜低的趋势。并且,释放量的大小明显受到光照强度的影响。【结论】外用MeJA喷雾处理可诱导茶树挥发物的产生和释放。

Variation in tea-plant volatiles induced by exogenous application of different concentrations of methyl jasmonate

Objectives] To clarify the effect of exogenous application of methyl jasmonate on the emission of volatile chemicals from Camellia sinesis. Methods] The headspace sampling method was used to extract volatiles from tea plants in vivo that had been treated with different concentrations of methyl jasmonate. A gas chromatograph mass spectrometer (GS-MS) system was then used to identify the volatiles extracted from the tea plants. Results] The results show that the composition and quantity of tea volatiles was affected by the concentration of methyl jasmonate applied to plants. Plants treated with 50 mL of methyl jasmonate emitted 10 monoterpenoids, including myrcene, terpinoloene, ocimeneetc; 7 sesquiterpenoids, including farnesene, nerolidol, bisaboleneetc; 5 amino acid derivatives, including benzyl alcohol, phenylacetonitrile, and indole; and 3 unknown compounds. However, treatment with 100 mL of methyl jasmonate only induced the emission of 7 volatiles. Different volatiles were emitted at different times following methyl jasmonate treatment. However, emissions of all volatiles tended to be higher during the day than at night. Moreover, the quantity of volatiles emitted was affected by the intensity of illumination. Conclusion] Exogenous application of methyl jasmonate can induce the production and emission of tea plant volatiles.