Yánez-Mendizábal Viviana, Falconí César E
AgroScience & Food Research Group, Universidad de Las Américas, Quito, Ecuador.
Departamento de Ciencias de la Vida, Carrera de Ingeniería Agropecuaria IASA I, Universidad de las Fuerzas Armadas (ESPE), Sangolquí, Ecuador.
Biotechnol Lett. 2021 Mar;43(3):719-728. doi: 10.1007/s10529-020-03066-x. Epub 2021 Jan 3.
To evaluate the role of the biocontrol agent Bacillus subtilis CtpxS2-1 in inducing lupin systemic resistance against anthracnose caused by Colletotrichum acutatum by lipopeptide production.
First, growth inhibition and thin layer chromatography-bioautography analysis confirmed that CtpxS2-1 cultures and their lipopeptide extracts, specifically fengycin, have strong antifungal activity against C. acutatum. Subsequent microscopic examination of these fungal inhibition zones showed mycelial pathogen deformations. PCR amplification of CtpxS2-1 confirmed the presence of genes encoding fengycins E and C, bacillomycin C, iturin A, and surfactins B and C. Based on this evidence, the effect of CtpxS2-1 and its lipopeptides on the induction of the lupin defence- and growth-related genes PR-1, PR-4, SOD-2, PIN-1 and PIN-3 was evaluated by RT-qPCR. In seedlings from roots treated with CtxpS2-1, a significant increase in the expression of these genes was induced. Efficacy assays showed that CtpxS2-1 treatment completely controlled anthracnose incidence (0.0%) compared with the untreated control. Furthermore, root and shoot growth in treated seedlings with CtpxS2-1 significantly increased due to disease control, as did the synthesis of the defence enzymes catalase, peroxidase and superoxide dismutase.
B. subtilis CtpxS2-1 is a key factor enhancing Andean lupin health by producing lipopeptides that damage C. acutatum cellular structures and inhibit their growth, as well as by inducing the expression of defence-related genes of lupin plants involved in systemic acquired resistance (SAR) against anthracnose.
评估生防菌枯草芽孢杆菌CtpxS2-1通过产生脂肽诱导羽扇豆对尖孢炭疽菌引起的炭疽病产生系统抗性的作用。
首先，生长抑制和薄层色谱-生物自显影分析证实，CtpxS2-1培养物及其脂肽提取物，特别是丰原素，对尖孢炭疽菌具有很强的抗真菌活性。随后对这些真菌抑制区的显微镜检查显示病原菌菌丝变形。CtpxS2-1的PCR扩增证实了编码丰原素E和C、芽孢杆菌霉素C、伊枯草菌素A以及表面活性素B和C的基因的存在。基于此证据，通过RT-qPCR评估了CtpxS2-1及其脂肽对羽扇豆防御和生长相关基因PR-1、PR-4、SOD-2、PIN-1和PIN-3诱导的影响。在用CtxpS2-1处理根部的幼苗中，这些基因的表达显著增加。功效试验表明，与未处理的对照相比，CtpxS2-1处理完全控制了炭疽病的发病率（0.0%）。此外，由于病害得到控制，用CtpxS2-1处理的幼苗的根和地上部分生长显著增加, 防御酶过氧化氢酶、过氧化物酶和超氧化物歧化酶的合成也显著增加。
枯草芽孢杆菌CtpxS2-1是增强安第斯羽扇豆健康的关键因素，它通过产生破坏尖孢炭疽菌细胞结构并抑制其生长的脂肽，以及诱导羽扇豆植物参与对炭疽病的系统获得性抗性（SAR）的防御相关基因的表达来实现。
