捷安肽素对采后柑桔青绿霉菌的抑制效果及作用机理

Postharvest Biological Control of Green and Blue Mold of Citrus Fruit by Jiean-peptide and Its Possible Antifungal Mechanism

将枯草芽孢杆菌(Bacillus subtilis)ZK菌株发酵产物捷安肽素用于柑桔采后的生物防治,研究了不同浓度、不同接入时间的捷安肽素对柑桔青霉菌(Penicillium italium)和绿霉菌(P.digitaum)的抑制效果,并与常用化学杀菌剂抑霉唑、咪鲜胺、甲基硫菌灵和多菌灵作比较.PDA平板上,柑桔绿霉菌比青霉菌对捷安肽素敏感.在柑桔果实上,53.86μg/mL捷安肽素处理下,柑桔青霉病和绿霉病的发病率分别为5%和5.28%,比对照低95%和94.72%.柑桔青霉病和绿霉病的病情指数分别为1.87和2.18,比对照低73.73和97.82.捷安肽素作用于柑桔绿霉菌1h内,菌丝体内K+含量迅速下降,为对照绿霉菌K+含量的37.53%,1h后菌丝体内K+含量变化趋于平缓.捷安肽素作用于柑桔绿霉菌12h内蛋白质、核酸缓慢泄漏,12h后蛋白质、核酸含量变化趋于平缓.实验结果表明:捷安肽素可以迅速改变绿霉菌细胞膜通透性.

Jiean-peptide produced by Bacillus subtilis ZK has broad-spectrum resistance to plant pathogens. Its effectiveness in controlling of green mole （Penicillium digitatum） and blue mold （ P. italicum） of citrus fruit was investigated by compared with four conventional fungicides ： imazalil, prochloraz, carbendazin and methyhhiophanate. The possible antifungal mechanism was also evaluated. In vitro test showed that the jiean-peptide was effective against green mold and blue mold, and provided better control of green mold. The in vivo test also indicated that the disease incidence of blue mold and green mold was 5% and 5.28%, and the disease severity was 1.87 and 2.18, respectively when inoculated with 53.86 μg/mL jiean-peptide. The decay incidence and disease severity were significantly reduced by the jiean-peptide compared with the control. When the jieanpeptide was inoculated for 48 h, 24 h, 12 h, 6 h after the pathogens＇ inoculation, its effect became lower compared with the inoculation at the same time. The action of jiean-peptide on non-growing cells of P. digitatum was tested. Compounds when absorbing at 260 nm and 280 nm were released and the amounts increased within 12 h compared with the control. Moreover, by the ICP measurement, the leakage of K^＋ occurred immediately in the presence of jiean-peptide within 1 h. All these results indicated that the jiean-peptide could change the membrane permeability of P. digitatum immediately and result in the leaking of nucleotides, proteins and K^＋ from cells. Fig 6, Tab 1, Ref 22