Samuel Gomes de Abreu¹, Levi Araújo Pinto ¹, Isabelle Mary Costa Pereira¹, Danilo de Menezes Daloso¹

Introduction – Cowpea is a crop of utmost importance for the northeast region of Brazil, mainly for its nutrional value and resistance to abiotic stresses. However, biotic stresses still represent a considerable threat to grain production, such as the cowpea severe mosaic virus (CPSMV). This virus is lethal to some cowpea cultivars, such as pitiuba, that does not defend itself against the virus, contrasting with the macaibo genotype, which is resistant to CPSMV. Objective – We aimed to investigate the difference between the metabolic responses of these two cultivars under CPSMV infection. Material and methods – It was used a metabolic flux approach using uniformly labeled 13C glucose (13C-glucose). Leaves were incubated in 13C-glucose under mock or CPSMV treatments and harvested after 2 and 8 hours. Metabolomics analysis wete performed using a well-established GC-MS platform. Results – It was possible to note a significant enrichment of 13C in myo-inositol, butyric acid, sucrose, glucose, succinic acid, raffinose and xylose. Beyond those metabolites, it was also possible to observe an increase in some Mn/M0 ratios, that reveal a rise of 13C in some isotopologes of metabolites, like in succinic acid, raffinose, xylose and a decrease of that ratio in malic acid. For the pitiuba, it was possible to note and increase R13C only on sucrose, and an increment in Mn/M0 ratio of succinic acid and xylose. Conclusion – The increase of R13C in sucrose indicates that the labeled glucose was assimilated and converted mainly into sucrose, which has a known importance in metabolic routes attached to plant defense. The lack of increment in other metabolites in pitiuba genotypes, that is susceptible to the viral infection, and the increase in R13C in macaibo metabolites cited above, might indicate the difference in defense routes activated between genotypes.

Agradecimentos: Agradeço aos demais envolvidos na elaboração desse trabalho, Levi A. Pinto, Isabelle M. C. Pereira e ao meu professor orientador Danilo M. Daloso.