Endophytic bacterial community diversity in two citrus cultivars with different citrus canker disease resistance

Abstract

The selective infection of Xanthomonas citri pv. citri to citrus cultivars is universally known, but it is not clari ed whether there is a relationship between endophytic bacteria and the resistance of host variety to canker disease. In order to explore the relationship, Satsuma mandarin and Newhall navel orange were collected respectively as samples of resistant or susceptible cultivars to citrus canker disease, and endophytic bacterial community of two citrus cultivars were analyzed by using a next-generation, Illumina-based sequencing approach. Simultaneously, the seasonal dynamics of endophytic bacterial community and dominant genera were analyzed. The results showed that there were four dominant groups including Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes in all samples at phylum level. Endophytic bacteria were the most abundant in spring samples, then in summer and autumn samples. There were some differences between endophytic bacterial community of resistant citrus and that of susceptible citrus to canker disease, and the endophytic bacteria of Satsuma mandarin are more abundant than that of Newhall navel orange. According to the analysis of dominant bacteria in two citrus cultivars, it was found that some endophytic bacteria with antagonistic characteristics existed universally in all samples, although the dominant bacteria in different seasonal sample were different. However, in Newhall navel orange of susceptible citrus to canker disease, there were not only some bacteria against Xanthomonas citri pv. citri, but also some cooperative bacteria of canker occurrence like Stenotrophomonas.

Predicting the impact of environmental factors on citrus canker through multiple regression

“…The Citrus orchards are attacked by Xanthomonas citri pv. citri ( Xcc ), which is a noxious pathogen causing citrus canker disease [ 8 – 10 ]. Xanthomonas citri is a straight, rod shaped, mono-flagellum, gram-negative bacterium with a wide host range [ 11 ].…”

Structure and Ecological Function of Fungal Endophytes from Stems of Different Mulberry Cultivars

“…Wu et al [ 17 ] analyzed the community structure and diversity of endophytes of four different resistant mulberry cultivars, and the results showed that numerous characteristics and the diversity of endophytes of resistant cultivars were significantly higher than those of susceptible cultivars. Endophytic bacterial populations of two citrus cultivars—the resistant satsuma mandarin and the susceptible Newhall navel orange—were analyzed through high-throughput sequencing, and the results showed that the differences in endophytic bacteria between citrus cultivars might be related to host resistance or susceptibility to citrus canker disease [ 18 ]. Endophytes of disease-resistant banana cultivars are more abundant and stable than those of disease-susceptible banana cultivars [ 19 ].…”