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VviNAC33 promotes organ de‐greening and represses vegetative growth during the vegetative‐to‐mature phase transition in grapevine
Author(s) -
D’Incà Erica,
Cazzaniga Stefano,
Foresti Chiara,
Vitulo Nicola,
Bertini Edoardo,
Galli Mary,
Gallavotti Andrea,
Pezzotti Mario,
Battista Tornielli Giovanni,
Zei Sara
Publication year - 2021
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.17263
Subject(s) - biology , microbiology and biotechnology , major facilitator superfamily , transcriptome , photosystem i , auxin , reprogramming , vegetative reproduction , repressor , gene , photosynthesis , botany , transcription factor , photosystem ii , mutant , genetics , gene expression
Summary Plants undergo several developmental transitions during their life cycle. In grapevine, a perennial woody fruit crop, the transition from vegetative/green‐to‐mature/woody growth involves transcriptomic reprogramming orchestrated by a small group of genes encoding regulators, but the underlying molecular mechanisms are not fully understood. We investigated the function of the transcriptional regulator VviNAC33 by generating and characterizing transgenic overexpressing grapevine lines and a chimeric repressor, and by exploring its putative targets through a DNA affinity purification sequencing (DAP‐seq) approach combined with transcriptomic data. We demonstrated that VviNAC33 induces leaf de‐greening, inhibits organ growth and directly activates the expression of STAY‐GREEN PROTEIN 1 ( SGR1 ), which is involved in Chl and photosystem degradation, and AUTOPHAGY 8f ( ATG8f ), which is involved in the maturation of autophagosomes. Furthermore, we show that VviNAC33 directly inhibits AUXIN EFFLUX FACILITATOR PIN1 , RopGEF1 and ATP SYNTHASE GAMMA CHAIN 1T ( ATPC1 ), which are involved in photosystem II integrity and activity. Our results show that VviNAC33 plays a major role in terminating photosynthetic activity and organ growth as part of a regulatory network governing the vegetative‐to‐mature phase transition.