ORIGINAL RESEARCH article
Front. Plant Sci.
Sec. Plant Physiology
This article is part of the Research TopicRegulation of Stress Tolerance in Plants by BiostimulantsView all 8 articles
Dual Benefits of Bacillus velezensis LJ-19: Contact-Dependent Biocontrol of Fusarium Wilt and Growth Promotion in Cucumber
Provisionally accepted
Li Songwei
Jingjing LiMinghui YuanJingxia RenYang JiaoLinjie ZhaoYeyun WangZihan YanJinYu LiJianfeng Du*Hongliang Wang*
Chenyu Yang*- Henan Institute of Science and Technology, Xinxiang, China
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Cucumber is an important economic crop widely cultivated globally. Fusarium wilt, 14 caused by Fusarium oxysporum f. sp. cucumerinum, seriously affects its yield and quality 15 and is difficult to control. Here, we isolated a novel Bacillus velezensis strain (LJ-19) 16 from cucumber rhizosphere, which exhibited pronounced antagonistic activity against 17 Fusarium oxysporum f. sp. cucumerinum and possessed plant growth-promoting traits. 18 Notably, the inhibition of Fusarium oxysporum f. sp. cucumerinum mycelial growth and 19 spore germination by LJ-19 was primarily contact-dependent, rather than mediated by 20 diffusible antibiotics. Meanwhile, LJ-19 enhanced the activities of key defense 21 enzymes—superoxide dismutase (SOD), peroxidase (POD), phenylalanine ammonia lyase 22 (PAL), and polyphenol oxidase (PPO), thereby contributing to plant protection, and the 23 transcript levels of defense-related genes, including Nonexpressor of pathogenesis-related 24 genes 1 (NPR1), Pathogenesis-related gene 3 (PR3), Lipoxygenase 1 (LOX1), Constitutive 25 triple response 1 (CTR1), and Phenylalanine ammonia-lyase 1 (PAL1), were up-regulated. 26 Pot experiments demonstrated that LJ-19 treatment significant increased the stem 27 thickness, fresh weight, leaf area, and overall biomass in cucumber. LJ-19 was also been 28 confirmed could thrive in nitrogen-free environment and solubilize inorganic phosphorus, 29 produce indole-3-acetic acid (IAA) and siderophores. Collectively, these findings 30 demonstrate that Bacillus velezensis LJ-19 suppresses cucumber Fusarium wilt via direct 31 antagonism and induction of systemic resistance. They also provide insights into the 32 molecular mechanisms by which LJ-19 controls Fusarium Wilt and promotes cucumber 33 growth, highlighting its potential as an effective biocontrol agent for sustainable 34 cucumber cultivation.
Keywords: Bacillus velezensis LJ-19, Fusarium Wilt, biocontrol, growth promotion, contact-dependent inhibition, induced systemic resistance
Received: 23 Sep 2025; Accepted: 26 Nov 2025.
Copyright: © 2025 Songwei, Li, Yuan, Ren, Jiao, Zhao, Wang, Yan, Li, Du, Wang and Yang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Jianfeng Du
Hongliang Wang
Chenyu Yang
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.