Project description:Southern corn leaf blight (SCLB), caused by Bipolaris maydis, poses a serious threat to maize production worldwide. In our previous study, Bacillus velezensis BV3 was isolated and demonstrated strong antagonistic activity against maize leaf spot pathogens and effective disease control in greenhouse experiments.
Project description:The ecological significance of light perception in non-phototrophic bacteria remains largely elusive. In terrestrial environments, diurnal oscillations in light are often temporally coupled to other environmental changes, including increased temperature and evaporation. Here we report that light functions as an anticipatory cue that triggers protective adaptations to tolerate a future rapid loss of environmental water in leaf-associated Pseudomonas syringae pv. syringae (Pss) and other terrestrial pseudomonads. Global transcriptome analyses in Pss showed that light control occurs almost entirely through a bacteriophytochrome photoreceptor that senses red, far-red and blue wavelengths and influences 30% of the Pss genome. Bacteriophytochrome-mediated light control disproportionally upregulates water-stress adaptation functions and confers enhanced fitness when cells encounter light prior to water limitation. These data demonstrate that non-phototrophic bacteria can use light as a cue to mount an adaptive anticipatory response against a physiologically unrelated but ecologically coupled stress.
Project description:In this study, we performed a comprehensive proteomic analysis of mango leaves inoculated with the leaf spot pathogen A. alternata. Down-regulated proteins during pathogen invasion and colonization were primarily associated with photosynthesis, the phenylpropanoid and flavonoid biosynthesis pathways, and phenylalanine metabolism. In contrast, significantly up-regulated proteins were involved in tyrosine metabolism and the MAPK signaling pathway, highlighting their critical role in host resistance to the leaf spot pathogen. These findings provide valuable data on protein expression changes, offering potential targets for developing novel management strategies to enhance control of leaf spot disease.
Project description:Arabidopsis thaliana (Col-0) plants were treated with BABA and gene expression differences to control plants were monitored after dip-inoculation with Pseudomonas syringae pv tomato DC3000. Keywords: transcript profiling, response to BABA-induced priming and infection 3 independant replicates were analyzed by two color co-hybridizations. Leaf RNA from Pseudomonas infected control plants (Cy3 labeled cDNA) was cohybridized with leaf RNA from Pseudomonas infected BABA pretreated plants (Cy5 labeled cDNA). Samples were collected 22 hours after bacterial inoculation. BABA pretreatment was performed two days before bacterial inoculation. To assess the effect of BABA alone on gene expression, leaf RNA from BABA treated plants (Cy5 labeled cDNA) was cohybridized with leaf RNA (Cy3 labeled cDNA) from water treated plants.
Project description:Apple leaf spot caused by the Alternaria alternata f. sp. mali (ALT1) fungus is one of the most devastating diseases of apple (Malus × domestica). We identified a hairpin RNA (hpRNA)-mediated small RNAs, MdhpRNA277, from apple (cv. ‘Golden Delicious’) that is induced by infection with ALT1. MdhpRNA277 produces mdm-siR277-1 and mdm-siR277-2, which target five R genes, MdRNL1, MdRNL2, MdRNL3, MdRNL4, and MdRNL5, that are expressed at high levels in the resistant apple variety ‘Hanfu’ and at low levels in the susceptible variety ‘Golden Delicious’ following ALT1 infection. MdhpRNA277 is strongly induced in ‘Golden Delicious’ but was not induced in ‘Hanfu’ following ALT1 inoculation. The promoter activity of MdhpRNA277 was much stronger in ‘Golden Delicious’ than in ‘Hanfu’ after ALT1 inoculation. We identified a single nucleotide polymorphism (SNP) in the MdhpRNA277 promoter region between the susceptible variety ‘Golden Delicious’ (pMdhpRNA277-GD) and resistant variety ‘Hanfu’ (pMdhpRNA277-HF). The transcription factor MdWHy binds to pMdhpRNA277-GD, but not to pMdhpRNA277-HF. Transgenic ‘GL-3’ apple lines expressing pMdhpRNA277-GD: MdhpRNA277 were more susceptible to ALT1 infection than were those expressing pMdhpRNA277-HF:MdhpRNA277 due to induced mdm-siR277 accumulation and low levels of expression of the five target R genes. The failure of MdWHy to bind to pMdhpRNA277-HF might contribute to the low levels of MdhpRNA277 and mdm-siR277-1/-2 expression and the high levels of R gene expression and resistance to Alternaria leaf spot in resistant apple varieties. We confirmed that the SNP in pMdhpRNA277 is associated with Alternaria leaf spot resistance by analyzing the progeny of three additional crosses. The SNP identified in this study could be used as a marker to distinguish between apple varieties that are resistant or susceptible to Alternaria leaf spot.
Project description:Mango bacterial leaf spot, which is caused by Xanthomonas critis pv. mangiferaeindicae (Xcm), poses a great threat to the development of mango planting industry.This work is the first to study the changes in gene and protein expressions in mango during Xcm infection. Our findings will provide new ideas for MBLS resistance and valuable genetic resources for the breeding of MBLS-resistant mango.
