Autoria: MELO, B. P.; LOURENCO, I. T.; FRAGA, O. T.; PINHEIRO, L. B.; LINS, C. B. de J.; MORGANTE, C. V.; ENGLER, J. A.; REIS, P. A. B.; SA, M. F. G. de; FONTES, E. P. B.

Resumo: NACs are plant-specifc transcription factors involved in controlling plant development, stress responses, and senescence. As senescence-associated genes (SAGs), NACs integrate age- and stress-dependent pathways that converge to programmed cell death (PCD). In Arabidopsis, NACSAGs belong to well-characterized regulatory networks, poorly understood in soybean. Here, we interrogated the soybean genome and provided a comprehensive analysis of senescence-associated Glycine max (Gm) NACs. To functionally examine GmNAC-SAGs, we selected GmNAC065, a putative ortholog of Arabidopsis ANAC083/VNI2 SAG, and the cell death-promoting GmNAC085, an ANAC072 SAG putative ortholog, for analyses. Expression analysis of GmNAC065 and GmNAC085 in soybean demonstrated (i) these cell death-promoting GmNACs display contrasting expression changes during age- and stress-induced senescence; (ii) they are co-expressed with functionally diferent gene sets involved in stress and PCD, and (iii) are diferentially induced by PCD inducers. Furthermore, we demonstrated GmNAC065 expression delays senescence in Arabidopsis, a phenotype associated with enhanced oxidative performance under multiple stresses, higher chlorophyll, carotenoid and sugar contents, and lower stress-induced PCD compared to wild-type. In contrast, GmNAC085 accelerated stress-induced senescence, causing enhanced chlorophyll loss, ROS accumulation and cell death, decreased antioxidative system expression and activity. Accordingly, GmNAC065 and GmNAC085 targeted functionally contrasting sets of downstream AtSAGs, further indicating that GmNAC85 and GmNAC065 regulators function inversely in developmental and environmental PCD.

Ano de publicação: 2021

Tipo de publicação: Artigo de periódico

Unidade: Embrapa Semiárido

Palavras-chave: Arabidopsis, Genoma, GmNAC065 expression, NAC SAGs, Planta, Soybeans