茉莉酸在巴西橡胶树伤害防卫结构形成中的作用

Jasmonic Acid in Formation of Defense Structures of Hevea brasiliensis

研究了巴西橡胶树(Hevea brasiliensis)芽接树的萌条受机械伤害时外施茉莉酸(JA)对2种防卫结构创伤周皮和乳管的形成的影响.结果表明:①割伤幼茎树皮直至形成层或刮伤幼茎树皮去掉表皮和2～3层皮层细胞,都能在6 d后看到诱导维管形成层分化出次生乳管.在伤口上施用JA或JA生物合成的前体亚麻酸(LA),能够使伤害诱导的乳管增加;而施JA生物合成的抑制剂indomethacin(IND)则产生抑制伤害诱导乳管分化的作用.②割伤或刮伤都能诱导形成创伤周皮,而在伤口施用JA和IND,JA可能不参与诱导创伤周皮的形成.③施用乙烯利和6-苄基腺嘌呤(BA)都不能引起创伤周皮形成,但BA能促进伤害诱导的创伤周皮细胞层数目增加.

The effects of jasmonic acid(JA)on the formation of defense structures,wound periderm and laticifers caused by wounding were studied by using the young stems in epicomic shoots of Hevea brasiliensis.In the young stem,the bark was cut into xylem or scraped to remove part of the bark,which induced differentiation of secondary laticifers6days after wounding.The wounding -caused laticifer differentiation was enhanced by exogenous JA or linolenic acid,the precursor of JA biosynthesis,and hindered by exogenous indomethacin(IND),inhibitor of JA biosynthesis.Bark cutting or scraping could induce formation of wound periderm.The experiments of application of JA and IND seemed to indicate that JA was not involved in the induction of wound periderm formation.Experiments also showed ethrel and N 6 -benzyl-adenine(BA)did not induce wound periderm,but the cell layer number of wound periderm increased when BA was applied.