RNase D Is Involved in 5S rRNA Degradation and Exopolysaccharide Production in Xanthomonas campestris pv. campestris
RNase D Is Involved in 5S rRNA Degradation and Exopolysaccharide Production in Xanthomonas campestris pv. campestris
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DOI：
10.1094/phyto-09-22-0327-r
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Dong-Jie Tang
中科院分区：
文献类型：
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作者：
Xin-Yi Chen;Shan-Shan Hu;Xiao-Can Xu;Ji-Liang Tang;Dong-Jie Tang
Ribonucleases (RNases) play critical roles in RNA metabolism and are collectively essential for cell viability. However, most knowledge about bacterial RNases comes from the studies on Escherichia coli; very little is known about the RNases in plant pathogens. The crucifer black rot pathogen Xanthomonas campestris pv. campestris ( Xcc) encodes 15 RNases, but none of them has been functionally characterized. Here, we report the physiological function of the exoribonuclease RNase D in Xcc and provide evidence demonstrating that the Xcc RNase D is involved in 5S rRNA degradation and exopolysaccharide (EPS) production. Our work shows that the growth and virulence of Xcc were not affected by deletion of RNase D but were severely attenuated by RNase D overexpression. However, deletion of RNase D in Xcc resulted in a significant reduction in EPS production. In addition, either deletion or overexpression of RNase D in Xcc did not influence the tRNAs tested, inconsistent with the finding in E. coli that the primary function of RNase D is to participate in tRNA maturation and its overexpression degrades tRNAs. More importantly, deletion, overexpression, and in vitro enzymatic analyses revealed that the Xcc RNase D degrades 5S rRNA but not 16S and 23S rRNAs that share an operon with 5S rRNA. Our results suggest that Xcc employs RNase D to realize specific modulation of the cellular 5S rRNA content after transcription and maturation whenever necessary. The finding expands our knowledge about the function of RNase D in bacteria.
