Potato is an important crop in Shanxi province located in north-central China. During 2019-2020, 319 potato leaf samples were collected from eight locations distributed in three major potato production areas in Shanxi. Bio-chip detection kit revealed the presence of several potato viruses, and among them potato virus Y (PVY) was the most common one, reaching the incidence of 87.8% of all symptomatic samples. The immuno-captured multiplex reverse transcription (RT)-PCR was used to identify strains for all 280 PVY-positive samples, unveiling 242 samples infected with a single strain of PVY (86.4%) and 38 (13.6%) with a mixed infection. Of samples with a single-strain infection, PVY -SYR-II accounted for 102 (42.1%), followed by PVYN-Wi (33, 13.6%) , PVY -SYR-I (28, 11.6%), 261-4 (22, 9.1%), PVYNTNa (20, 8.3%), PVYNTNb (19, 7.9%), and PVY -SYR-III (18, 7.4%). Seven isolates representing different recombinants were selected for whole genome sequencing. Phylogenetic and recombination analyses confirmed the RT-PCR based strain typing for all seven strains of PVY found in Shanxi. SXKL-12 is the first SYR-III strain from potato reported from China. However, unlike that in other known SYR-III isolates, the region positioned from 1,764 to1,902 nt in SXKL-12 shared the highest sequence identity of 82.2% with an uncharacterized PVY isolate, JL-23, from China. Interestingly, the PVYN-Wi isolate SXZY-40 also possessed a more divergent sequence for the region positioned from 6,156 to 6,276 nt than other N-Wi isolates known to date, sharing the highest identity of 86.6% with an uncharacterized Chinese PVY isolate, JL-11. Pathogenicity analysis of dominant strains PVY -SYR-II and PVYN-Wi in six local popular potato cultivars revealed that Kexin 13, Helan 15 and Jizhangshu 12 were susceptible to these two strains with mild mottling or mosaic symptoms expression, while three cultivars, Jinshu 16, Qingshu 9, Xisen 6 were found fully resistant.

Background: N6-methyladenosine (m6A) is the most abundant modification of the mRNA, which plays multiple roles in the regulation of biological process. The m6A regulatory genes have been studied in various plant species. However, comprehensive analysis of m6A-related genes in the common bean (Phaseolus vulgaris) are still unperformed. Results: In our study, a total of 31 m6A regulatory genes were identified from common bean genome and grouped into three categories including writers, erasers and readers. The expansion of the m6A families in common bean was mostly fueled by segmental duplication or whole genome duplication events. Then, we performed a comprehensive analysis of chromosomal distribution, collinearity relationship, evolutionary selection, gene structure, conserved domain, conserved motif, cis-acting elements, protein-protein interaction with several bioinformatic tools. Moreover, the transcriptomic data exposed that m6A related genes were differentially expressed on the primary true leaf and systemic leaf of susceptible and resistant bean varieties. Our RT-qPCR tests revealed that the expression of all m6A related genes varied through time upon viral infection. Conclusion；In this study, a thorough and systematic genome-wide analysis was performed for m6A regulatory genes of common bean. Our results will provide evidence for discovery of the functions of the m6A components and their family proteins, facilitating further study of the m6A-mediated mechanism in common beans during viral infection.

Bean common mosaic disease is one of the most destructive diseases of the common bean, which is one of the most important legumes worldwide. It is caused by two closely related potyviruses: bean common mosaic virus (BCMV) and bean common mosaic necrosis virus (BCMNV). Both viruses have spread to all the common bean-growing areas worldwide and have become a major challenge in bean production. In this review, we summarized the biology and diversity of BCMV and BCMNV, discussed the current knowledge on the resistance genes of BCMV, and finally pointed out the future prospects for the control of bean common mosaic disease.