AUTHOR=Zhou Jing-Ru , Li Juan , Lin Jia-Xin , Xu Hui-Mei , Chu Na , Wang Qin-Nan , Gao San-Ji 

TITLE=Genome-wide characterization of cys-tathionine-β-synthase domain-containing proteins in sugarcane reveals their role in defense responses under multiple stressors

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.985653

DOI=10.3389/fpls.2022.985653

ISSN=1664-462X

ABSTRACT=<p>Cys-tathionine-β-synthase (CBS) domain-containing proteins (CDCPs) are essential for regulating plant responses to various biotic and abiotic stressors. This study describes the systematic identification and characterization of CDCP family genes in <italic>Saccharum spontaneum</italic>. A total of 95 <italic>SsCDCP</italic> genes and eight phylogenetic groups were identified that were distributed over 29 chromosomes of the AP85-441 genome. Most (78/95) <italic>SsCDCPs</italic> underwent fragment duplication events, and 64 gene pairs were located in synteny blocks. Expression profiling of nine <italic>ShCDCP</italic>s was also carried out in the <italic>Saccharum</italic> spp. cultivars ROC22 and MT11-611 that are resistant and susceptible to red stripe, respectively, in response to: (i) Infection by the bacterial pathogen <italic>Acidovorax avenue</italic> subsp. <italic>avenae</italic> (<italic>Aaa</italic>); (ii) abiotic stressors (drought and salinity); and (iii) exogenous salicylic acid (SA) treatment. Members of one gene pair (<italic>ShCBSD-PB1-5A</italic> and <italic>ShCBSD-PB1-7A-1</italic>) with a fragment duplication event acted as negative regulators in sugarcane under four stresses, as supported by the significantly decreased expression levels of <italic>ShCBSD-PB1-5A</italic> (23–83%) and <italic>ShCBSD-PB1-7A-1</italic> (15–75%) at all-time points, suggesting that they have functional redundancy. Genes in another pair, <italic>ShCBS-4C</italic> and <italic>ShCBS-4D-1</italic>, which have a fragment duplication event, play opposing regulatory roles in sugarcane exposed to multiple stresses, particularly <italic>Aaa</italic> and NaCl treatments. <italic>ShCBS-4C</italic> expression was significantly decreased by 32–77%, but <italic>ShCBS-4D-1</italic> expression was dramatically upregulated by 1.2–6.2-fold in response to <italic>Aaa</italic> treatment of both cultivars across all-time points. This result suggested that both genes exhibited functional divergence. Meanwhile, the expression of <italic>SsCBSDCBS-5A</italic> was significantly upregulated in ROC22 by 1.4–4.6-fold in response to the four stressors. These findings provide important clues for further elucidating the function of <italic>ShCDCP</italic> genes in sugarcane responding to a diverse range of stresses.</p>