Jasmonates are key factors inducing exudation of gum polysaccharides : Mode of action of jasmonates focusing on ethylene interaction

本研究旨在了解茉莉酸类化合物(Jas)诱导多种植物特别是核果树和郁金香树胶形成的机制。(1)外源茉莉酸类化合物对桃树、杏、酸樱桃和李子等蔷薇科植物诱导树胶形成。外源乙烯(Ethephon：乙烯生成化合物，Eth)也能诱导这些植物树胶的形成。Jas和Eth同时应用对果胶形成有协同作用，说明Jas和Eth在核果果树中是通过相互作用来调控树胶形成的。茉莉酸的抑制剂减少了乙烯诱导的李果实胶体的形成，而乙酸乙酯的抑制剂不影响茉莉酸诱导的果胶形成。在李果实上施用茉莉酸，S提高了乙烯的产量，而乙烯不能提高茉莉酸的内源水平。这些结果表明，在核果树中，Jas通过与乙烯的相互作用在诱导树胶形成中起重要作用。(2)在郁金香(Tulipa gesne…More Riana L.cv.APELHOORTN)，利用GC-MS成功地鉴定出了诱导树胶的内源因素茉莉酸(JA)和茉莉酸甲酯(JA-Me)。以氚标记的JAs为内标，估算了郁金香茎中JA+JA-Me的总量，约为70~80 ng/gFW。JA和JA-Me的应用显著地诱导了Eth的产生。喷施乙酸乙酯对郁金香茎中茉莉酸含量影响不大，但不会引起胶凝现象。这些结果表明，JAS是诱导郁金香树胶形成的内源因子。JAs促进了Eth的产生，但施加乙烯对JAs的内源水平没有影响。茉莉酸能显著降低郁金香中可溶性糖的总量，而乙烯不能，而茉莉酸和乙烯都能促进郁金香新梢的衰老，表现为叶绿素的损失。这些结果表明，JAS在郁金香枝条上诱导的胶体形成与糖代谢有关。茉莉酸类物质在郁金香枝条胶凝过程中的作用方式与乙烯生成、糖代谢和衰老的关系将被讨论。较少

The purpose of this study was to know the mechanism of jasmonates(JAs) to induce gum formation in various plants especially in stone-fruit trees and tulips.(1)Exogenous application of jasmonates to various plant species in Rosaceae such as peach, apricot, sour cherry and plum induced gum formation. Exogenous applied ethylene (ethephon : ethylene-generating compound, Eth) also induced gum formation in these plant species. Simultaneous application of JAs and Eth showed synergistic effect on gum formation, suggesting that in stone-fruit trees JAs and Eth regulate gum formation by interacting with each other. An inhibitor of JA reduced Eth-induced gum formation in plum fruits, while that of Eth did not affect JA-induced one. The application of JAs to plum fruits s enhanced Eth production, while that of Eth did not increase endogenous level of JAs. These suggest that in stone-fruit trees, JAs play an important role in inducing gum formation by interacting with Eth.(2)In tulips (Tulipa gesne … More riana L.cv.Apeldoorn), based on the procedure to detect the endogenous factors inducing gum, jasmonic acid(JA) and methyl jasmonate (JA-Me) were successfully identified using a GC-MS. Total amounts of JAs (JA+JA-Me) in tulip stems were estimated with deuterium labeled ones as internal standards, being about 70 to 80 ng/g Fw. The application of JA and JA-Me substantially induced gums with Eth production. The application of Eth, however, induced no gummosis although it only slightly affected content of JAs in tulip stems. These results suggest that JAs are endogenous factors to induce gummosis in tulips. JAs stimulated Eth production, but application of ethylene had no effect on endogenous levels of JAs. JAs strongly decreased the total amount of soluble sugars in tulip, but Ethn did not, while both JA-Me and Eth stimulated senescence of the shoot shown by the loss of chlorophyll. These results suggest that gum formation induced by the application of JAs in tulip shoots is connected with the sugar metabolism. The mode of action of jasmonates in gummosis of tulip shoots will be discussed in relation to Eth production, sugar metabolism and senescence. Less