Plant Pathology Section, Crop Protection Division, ICAR-Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, 641007, India.
Mol Biol Rep. 2021 Mar;48(3):2053-2061. doi: 10.1007/s11033-021-06140-3. Epub 2021 Mar 3.
Red rot caused by Colletotrichum falcatum, is one of the economically important disease of sugarcane and breeding for resistant varieties is considered to be the major solution to manage the disease. However, breakdown of red rot resistance become usual phenomenon due to development of newer races by culture adaptation on newly released varieties. Hence it is needed to characterize the genes responsible for pathogen virulence in order to take care of host resistance or to manage the disease by other methods. The transcript studies gave foundation to characterize the huge number of pathogenicity determinants and their role in pathogenesis. Here we studied role of two important genes viz., Glucose Transporter (GT) and Sucrose Non-Fermenting1 (SNF1) during pathogenesis of C. falcatum, which said to be involved in carbon source metabolism. Sugar metabolism has a vital role in disease progression of C. falcatum by regulating their cell growth, metabolism and development of the pathogen during various stages of infection. The present study was aimed to find out the role of GT and SNF1 genes in response to pathogenicity by RNA silencing (RNAi) approach. Knock-down of the target pathogenicity gene homologs in standard C. falcatum isolate Cf671 was carried out by amplifying sense and antisense fragments of targets individually using pSilent-1 vector. The expression cassette was cloned into the binary vector pCAMBIA1300 followed by fungal transformation through Agarobacterium mediated transformation. Resulted mutants of both the genes showed less virulence compared to wild type isolate. Simultaneously, both the mutants did not produce spores. Moreover, the molecular confirmation of the mutants displayed the expression of hygromycin gene with reduced expression of the target gene during host-pathogen interaction. Knockdown of the pathogenicity related genes (GT and SNF1) by RNAi approach corroborate the possible role of the genes in causing the disease.
镰刀菌红色腐烂病是甘蔗的一种重要经济病害，培育抗性品种被认为是控制该病害的主要方法。然而，由于新的菌株通过对新释放品种的培养适应而发展，红色腐烂病抗性的崩溃成为一种常见现象。因此，有必要对负责病原菌毒力的基因进行特征描述，以便对宿主的抗性进行处理，或者通过其他方法来管理病害。转录研究为描述大量的致病性决定因素及其在发病机制中的作用奠定了基础。在这里，我们研究了两个重要基因（葡萄糖转运蛋白（GT）和蔗糖非发酵 1（SNF1））在镰刀菌发病过程中的作用，它们被认为参与了碳源代谢。糖代谢在镰刀菌的发病过程中起着至关重要的作用，通过调节细胞生长、代谢以及病原体在感染各个阶段的发育来控制疾病的进展。本研究旨在通过 RNA 干扰（RNAi）方法发现 GT 和 SNF1 基因在响应致病性方面的作用。使用 pSilent-1 载体分别扩增靶标致病性基因同源物的正义和反义片段，对标准镰刀菌分离株 Cf671 中的靶标基因进行 RNA 干扰（RNAi）敲低。表达盒被克隆到二元载体 pCAMBIA1300 中，然后通过琼脂杆菌介导的转化进行真菌转化。与野生型分离株相比，两个基因的突变体表现出较低的毒力。同时，两个突变体都不产生孢子。此外，突变体的分子验证显示，在与宿主的相互作用中，潮霉素基因的表达伴随着靶基因表达的降低。通过 RNAi 方法敲低与致病性相关的基因（GT 和 SNF1），证实了这些基因在引起疾病方面的可能作用。
