Höke D, Dräger B
Institute of Pharmaceutical Biology, Faculty of Pharmacy, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany.
Plant Biol (Stuttg). 2004 Mar-Apr;6(2):206-13. doi: 10.1055/s-2004-817797.
Calystegines are alkaloidal glycosidase inhibitors. They accumulate predominantly in young and meristemic parts of Calystegia sepium (Convolvulaceae). C. sepium, bindweed, infests meadows and cereal fields and is difficult to control chemically. Fungal pathogens against C. sepium are established as mycoherbicides. Stagonospora convolvuli LA39 attacks C. sepium and does not affect crop plants, but young plants of C. sepium are less susceptible to the fungus. The interaction of Stagonospora convolvuli with calystegines was investigated. Further, endophytic fungi of several classes were isolated from wild-grown Calystegia sepium leaves, and selected strains were tested for interaction with calystegines. Fungal growth on agar containing calystegines was not affected considerably. Plants in climate chambers were infected with an endophyte, Phomopsis, and with the fungal pathogen, Stagonospora convolvuli. Calystegine levels were measured in infected and non-infected plant tissues. Accumulation depended on developmental stage of the plant tissue and was not influenced by infection. Acid invertase was measured from fungal mycelia and from infected and non-infected plant tissues. Fungal acid invertase activity was not inhibited by 10 mM calystegine B (2), while invertase from C. sepium leaves was inhibited. It is concluded that calystegines do not inhibit fungal development and sucrose consumption under the conditions of the present investigation, but may act by redirection of plant carbohydrate metabolism.
旋花茄生物碱是一类生物碱糖苷酶抑制剂。它们主要积累在旋花科植物篱打碗花的幼嫩和分生组织部位。篱打碗花侵扰草地和谷物田，且化学防治难度较大。针对篱打碗花的真菌病原体已被开发为微生物除草剂。旋花链格孢LA39可侵染篱打碗花，且不影响农作物，但篱打碗花的幼苗对该真菌的敏感性较低。研究了旋花链格孢与旋花茄生物碱之间的相互作用。此外，从野生篱打碗花叶片中分离出几类内生真菌，并对选定菌株与旋花茄生物碱的相互作用进行了测试。在含有旋花茄生物碱的琼脂上，真菌生长未受到显著影响。在气候箱中，将植物分别感染内生真菌拟茎点霉和真菌病原体旋花链格孢。测定了感染和未感染植物组织中的旋花茄生物碱水平。其积累取决于植物组织的发育阶段，不受感染影响。测定了真菌菌丝体以及感染和未感染植物组织中的酸性转化酶。10 mM的旋花茄生物碱B(2)对真菌酸性转化酶活性没有抑制作用，而篱打碗花叶片中的转化酶则受到抑制。得出的结论是，在本研究条件下，旋花茄生物碱不会抑制真菌发育和蔗糖消耗，但可能通过改变植物碳水化合物代谢起作用。
