Complete Genome Sequence of Bacillus velezensis TH-1, a Candidate Biocontrol Bacterium from China.

Bacillus velezensis TH-1 is a plant growth-promoting rhizobacteria with biocontrol potential that was isolated from the rhizosphere of Sophora tonkinensis Radix. Our previous results showed that strain TH-1 demonstrated effective biocontrol activity against root rot of Sophora tonkinensis Radix and bacterial wilt of ginger. Currently, only a few whole-genome sequences of biocontrol strains isolated from the rhizosphere of medicinal plants are available. We report, here, the complete genome sequence of B. velezensis TH-1. The size of TH-1 genome is 3,929,846 bp that consists of 3,900 genes with a total GC content of 46.48%. The strain TH-1 genome has 3,661 coding genes, 86 transfer RNAs, 27 ribosomal RNAs, and 16 small RNAs. Moreover, we identified nine gene clusters coding for the biosynthesis of antimicrobial compounds. The genomic information of TH-1 will provide resources for the study of biological control mechanisms and plant-microbe interactions. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Huanglongbing Control: Perhaps the End of the Beginning.

Huanglongbing (HLB) is one of the most destructive citrus plant diseases worldwide. It is associated with the fastidious phloem-limited α-proteobacteria 'Candidatus Liberibacter asiaticus', 'Ca. Liberibacter africanus' and 'Ca. Liberibacter americanus'. In recent years, HLB-associated Liberibacters have extended to North and South America. The causal agents of HLB have been putatively identified, and their transmission pathways and worldwide population structure have been extensively studied. However, very little is known about the epidemiologic relationships of Ca. L. asiaticus, which has limited the scope of HLB research and especially the development of control strategies. HLB-affected plants produce damaged fruits and die within several years. To control the disease, scientists have developed new compounds and screened existing compounds for their antibiotic and antimicrobial activities against the disease. These compounds, however, have very little or even no effect on the disease. The aim of the present review was to compile and compare different methods of HLB disease control with newly developed integrative strategies. In light of recent studies, we also describe how to control the vectors of this disease and the biological control of other citrus plant pathogens. This work could steer the attention of scientists towards integrative control strategies.