ScAOC1, an allene oxide cyclase gene, confers defense response to biotic and abiotic stresses in sugarcane

• Published in: Plant cell reports 2020-12, Vol.39 (12), p.1785-1801
• Main Authors: Sun, Tingting, Cen, Guangli, You, Chuihuai, Lou, Wenyue, Wang, Zhoutao, Su, Weihua, Wang, Wenju, Li, Damei, Que, Youxiong, Su, Yachun
• Format: Article
• Language: English
• Subjects: Abiotic stress; Abscisic acid; Allene; Biological activity; Biomedical and Life Sciences; Biosynthesis; Biotechnology; Cell Biology; Chromosome Mapping; Cloning; Cold stimuli; Cold tolerance; Cold-Shock Response; E coli; Escherichia coli - genetics; Evolution, Molecular; Fusarium - pathogenicity; Gene Expression Regulation, Plant; Homology; Intramolecular Oxidoreductases - chemistry; Intramolecular Oxidoreductases - genetics; Intramolecular Oxidoreductases - metabolism; Jasmonic acid; Life Sciences; Mannitol; Mannitol - pharmacology; Multigene Family; Nicotiana - genetics; Nicotiana - microbiology; Original Article; Phylogeny; Plant Biochemistry; Plant Growth Regulators - pharmacology; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Sciences; Plant stress; Plants, Genetically Modified; Promoter Regions, Genetic; Ralstonia solanacearum - pathogenicity; Regulatory Sequences, Nucleic Acid; Saccharum - drug effects; Saccharum - genetics; Saccharum - physiology; Saccharum spontaneum; Smut; Sodium chloride; Sodium Chloride - pharmacology; Sporisorium scitamineum; Stereoisomerism; Stress, Physiological - physiology; Sugarcane
• ISSN: 0721-7714; 1432-203X
• DOI: 10.1007/s00299-020-02606-z

Key message An allene oxide cyclase gene which is involved in defense against biotic and abiotic stresses was cloned and characterized in sugarcane. Allene oxide cyclase (AOC), a key enzyme in jasmonate acid (JA) biosynthesis, affects the stereoisomerism and biological activity of JA molecules, and plays an important role in plant stress resistance. In this study, four SsAOC alleles ( SsAOC1–SsAOC4 ), which shared similar gene structure and were located on Chr1A, Chr1B, Chr1C, and Chr1D, respectively, were mined from sugarcane wild species Saccharum spontaneum , and a homologous gene ScAOC1 (GenBank Accession Number: MK674849) was cloned from sugarcane hybrid variety Yacheng05-179 inoculated with Sporisorium scitamineum for 48 h. ScAOC1 and SsAOC1–SsAOC4 were alkaline, unstable, hydrophilic, and non-secretory proteins, which possess the same set of conserved motifs and were clustered into one group in the phylogenetic analysis. ScAOC1 was expressed in all sugarcane tissues, but with different levels. After infection by S. scitamineum , the transcripts of ScAOC1 were increased significantly both in the smut-susceptible (ROC22) and resistant (Yacheng05-179) varieties, but its transcripts were more accumulated and lasted for a longer period in the smut-resistant variety than in the smut-susceptible one. ScAOC1 was down-regulated under MeJA and NaCl treatments, but up-regulated under SA, ABA, PEG, and cold stresses. Transiently overexpressing ScAOC1 gene into Nicotiana benthamiana leaves regulated the responses of N. benthamiana to two pathogens Ralstonia solanacearum and Fusarium solani var. coeruleum . Furthermore, prokaryotic expression analysis showed overexpression of ScAOC1 in Escherichia coli BL21 could enhance its tolerance to NaCl, mannitol, and cold stimuli. These results indicated that ScAOC1 may play an active role in response to biotic and abiotic stresses in sugarcane.