茶菁經小綠葉蟬叮咬前後蛋白質體學及香氣成份變化之研究

Abstract

椪風茶又名東方美人茶，為台灣特有生產之茶類，具有特殊之蜜香味及果香味，其原料來自於被小綠葉蟬—smaller green leafhopper Paoli ( Jacobiasca formosana Paoli ) 所叮咬過之茶菁。已知必須是經過小綠葉蟬叮咬之茶菁，才能製成風味良好之椪風茶。為了探究小綠葉蟬叮咬茶菁對茶樹造成之生理變化與椪風茶品質之可能影響，因而進行本研究。在蛋白質體學研究方面，以2D-PAGE電泳分析，我們發現受小綠葉蟬叮咬後的茶菁中，有四個蛋白質之表現量明顯增加，經蛋白質資料庫比對，它們分別為heat shock protein，superoxide dismutase，glyoxalase，以及thiosulfate sulfurtransferase (rhodanese)，而這些蛋白質或酵素，已知分別與植物之防禦或是逆境耐性之產生機制有關。經GC/MS分析茶菁的芳香物質，受小綠葉蟬叮咬後的茶菁含有明顯之 benzaldehyde, 3-carene, linalool, linalool oxides, linalool derivatives, benzyl nitrile, indole,alpha-farnesene, methyl salicylate, benzoic acid及cis-jasmone 等成分，推測這是椪風茶具有特殊香味之來源之一。綜合以上結果得知，小綠葉蟬叮咬茶樹並吸食芽葉韌皮部汁液，對茶樹造成逆境，因而引發茶菁之相關防禦機制，而這些揮發性物質則可能扮演訊息傳導、忌避害蟲，或是吸引害蟲天敵之角色。

Pong-Fong tea, also named Oriental Beauty tea, a unique tea only produced in Taiwan, is famous for the honey-like and ripen-fruit-like aroma. To use the tea leaves infested by a kind of small tea insect, smaller green leafhopper (Jacobiasca formosana Paoli), as the tea making material is the characteristic in production of Pong-Fong tea. Therefore, the feeding damage on the tea leaves is thought the key effect to the aroma formation of Pong-Fong tea. In the proteomic analysis, the elevated expression of four proteins was observed, including a heat shock protein, a superoxide dismutase, a glyoxalase, and a thiosulfate sulfurtransferase, which has been reported to be involved in plant stress or defense reactions. Through the volatile compounds analysis by GC/MS, we found that tea leaves with feeding damage by J. formosana Paoli contained more benzaldehyde, 3-carene, linalool, linalool oxides, linalool derivatives, benzyl nitrile, indole, alpha-farnesene, methyl salicylate, benzoic acid and cis-jasmone. It is concluded that the feeding damage in tea leaves by the phloem feeding insect, J. formosana Paoli, resulted to their stress and defense response, and the volatile compounds were emitted probably for signaling, herbivore deterrence and attraction for the predators or parasitoids of the herbivore.