Liu Zongling, Lan Xianruan, Li Xiufang, Zhao Haiyun, Gan Jiaming, Li Ru, Chen Baoshan
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China.
Guangxi Key Laboratory of Sugarcane Biology, College of Agriculture, Guangxi University, Nanning 530004, China.
J Fungi (Basel). 2022 Feb 21;8(2):209. doi: 10.3390/jof8020209.
Sugarcane smut caused by the basidiomycetes fungus is a devastating disease for the sugarcane industry worldwide. As the initial step, the smut teliospores germinate on sugarcane buds, and subsequently, the mycelium infects the bud tissues. However, chemical signals that induce spore germination are still unknown. By comparison of the behavior of the teliospores on the buds of both resistant and susceptible varieties, we found that spore germination rates were significantly lower on the buds of resistant cultivars ZZ1, ZZ6, and ZZ9 than on the susceptible varieties GT42 and ROC22. It was found that the levels of hexacosanol and octacosanol were higher on the buds of smut-susceptible varieties than on the smut-resistant varieties. These observations were extended to the smut-resistant and smut-susceptible sub-genetic populations derived from the cross of ROC25 and YZ89-7. In artificial surface assays, we found that hexacosanol and octacosanol promoted smut teliospore germination. Transcriptome analysis of smut teliospores under the induction by octacosanol revealed that genes in the MAPK signaling pathway and fatty acid metabolism were significantly differentially expressed. Overall, our results provide evidence that alkanol plays important roles in smut teliospore germination and thus could be used as a potential marker for smut resistance in sugarcane breeding programs.
由担子菌真菌引起的甘蔗黑穗病是全球甘蔗产业的一种毁灭性病害。作为第一步，黑穗病冬孢子在甘蔗芽上萌发，随后，菌丝体感染芽组织。然而，诱导孢子萌发的化学信号仍然未知。通过比较冬孢子在抗病和感病品种芽上的行为，我们发现，在抗病品种ZZ1、ZZ6和ZZ9的芽上，孢子萌发率显著低于感病品种GT42和ROC22。结果发现，感病品种芽上的二十六醇和二十八醇水平高于抗病品种。这些观察结果扩展到了由ROC25和YZ89 - 7杂交产生的抗病和感病亚遗传群体。在人工表面试验中，我们发现二十六醇和二十八醇促进了黑穗病冬孢子的萌发。二十八醇诱导下黑穗病冬孢子的转录组分析表明，丝裂原活化蛋白激酶（MAPK）信号通路和脂肪酸代谢中的基因存在显著差异表达。总体而言，我们的结果提供了证据，表明链烷醇在黑穗病冬孢子萌发中起重要作用，因此可作为甘蔗育种计划中黑穗病抗性的潜在标记。
