AUTHOR=Zhang He , Ye Zi , Liu Zhixin , Sun Yu , Li Xinyu , Wu Jiao , Zhou Guangzhen , Wan Yinglang 

TITLE=The Cassava NBS-LRR Genes Confer Resistance to Cassava Bacterial Blight

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.790140

DOI=10.3389/fpls.2022.790140

ISSN=1664-462X

ABSTRACT=<p>Cassava bacterial blight (CBB) caused by <italic>Xanthomonas axonopodis</italic> pv. <italic>manihotis</italic> (<italic>Xam</italic>) seriously affects cassava yield. Genes encoding nucleotide-binding site (NBS) and leucine-rich repeat (LRR) domains are among the most important disease resistance genes in plants that are specifically involved in the response to diverse pathogens. However, the <italic>in vivo</italic> roles of <italic>NBS-LRR</italic> remain unclear in cassava (<italic>Manihot esculenta</italic>). In this study, we isolated four <italic>MeLRR</italic> genes and assessed their expression under salicylic acid (SA) treatment and <italic>Xam</italic> inoculation. Four <italic>MeLRR</italic> genes positively regulate cassava disease general resistance against <italic>Xam</italic> via virus-induced gene silencing (VIGS) and transient overexpression. During cassava-<italic>Xam</italic> interaction, <italic>MeLRRs</italic> positively regulated endogenous SA and reactive oxygen species (ROS) accumulation and pathogenesis-related gene 1 (<italic>PR1</italic>) transcripts. Additionally, we revealed that <italic>MeLRRs</italic> positively regulated disease resistance in <italic>Arabidopsis</italic>. These pathogenic microorganisms include <italic>Pseudomonas syringae</italic> pv. <italic>tomato</italic>, <italic>Alternaria brassicicola</italic>, and <italic>Botrytis cinerea</italic>. Our findings shed light on the molecular mechanism underlying the regulation of cassava resistance against <italic>Xam</italic> inoculation.</p>