白光光照对交链孢毒素合成的调控研究

Regulation of white light illumination on the synthesis of Alternaria toxins

目的研究白光光照对交链孢(Alternaria)毒素合成的影响。方法在光/暗培养条件下,比较分析白光光照对2种交链孢菌株(ATCC 66981和Pear-3)的菌丝生长、孢子形成以及毒素合成的影响。结果持续白光照射对交链孢菌丝生长影响不显著,而显著抑制其孢子形成。光照刺激交链孢菌ATCC66981中交链孢酚(alternariol, AOH)、交链孢酚单甲醚(alternariol monomethyl ether, AME)和腾毒素(tentoxin, TEN)3种毒素的产生。菌株持续光照培养30d,AOH、AME和TEN毒素浓度分别为120、182和173?g/L;较之黑暗培养,分别增加了1.1、5.9和9.6倍。光照抑制交链孢菌Pear-3中细交链孢菌酮酸(tenuazonic acid, TeA)毒素的合成。菌株光照培养6 d, TeA毒素浓度达到142?g/L;而黑暗培养后其浓度高达325?g/L,毒素产率增加了1.3倍。结论光照不影响交链孢菌丝生长,而对孢子形成影响显著;持续白光照射能够促进交链孢中AOH、AME和TEN毒素的产生,而抑制TeA毒素的产生。

Objective To study the effect of white light illumination on the synthesis of Alternaria toxins. Methods The effects of white light illumination on mycelial growth, sporulation and toxin synthesis of 2 strains of Alternaria alternata(ATCC 66981 and Pear-3) were compared under light/dark culture conditions. Results Continuous white light irradiation had no significant effect on the growth of Alternaria alternata, but significantly inhibited sporulation. The light stimulated the production of 3 kinds of toxins, Alternariol(AOH), alternariol monomethyl ether(AME) and tenoxin(TEN) in Alternaria alternata ATCC 66981. The strain was cultured for 30 d, and the concentrations of AOH, AME and TEN toxins were 120, 182 and 173 ?g/L, respectively. Compared with the dark culture, the yield of AOH, AME and TEN increased by 1.1, 5.9 and 9.6 times, respectively. Illumination inhibited the tenuazonic acid(TeA) biosynthesis in Alternaria alternata Pear-3. Under 6 days light culture, the TeA content had already been 142 ?g/L, but the concentration of TeA reached up to 325 μg/L under the dark condition, and its toxin yield increased by 1.3 times. Conclusion Light does not affect the growth of Alternaria alternata, but has a significant effect on sporulation;continuous white light irradiation can promote the production of AOH, AME and TEN toxins in Alternaria, and inhibit the production of TeA toxin.