NPR1 has been found to be a key transcriptional regulator in some plant defence responses. There are nine We used bioinformatics and reverse genetics approaches to study the expression and function of each We found six members of We discovered a new mode of NPR1 action in wheat at the
- Award ID(s):
- 1758994
- NSF-PAR ID:
- 10168396
- Date Published:
- Journal Name:
- International Journal of Molecular Sciences
- Volume:
- 20
- Issue:
- 13
- ISSN:
- 1422-0067
- Page Range / eLocation ID:
- 3356
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Summary NPR1 homologues (TaNPR1 ) in wheat, but little research has been done to understand the function of thoseNPR1 ‐like genes in the wheat defence response against stem rust (Puccinia graminis f. sp.tritici ) pathogens.TaNPR1 .TaNPR1 located on homoeologous group 3 chromosomes (designated asTaG3NPR1 ) and three on homoeologous group 7 chromosomes (designated asTaG7NPR1 ). The group 3 NPR1 proteins regulate transcription of SA‐responsivePR genes. Downregulation of all theTaNPR1 homologues via virus‐induced gene co‐silencing resulted in enhanced resistance to stem rust. More specifically downregulatingTaG7NPR1 homeologues orTa7ANPR1 expression resulted in stem rust resistance phenotype. By contrast, knocking downTaG3NPR1 alone did not show visible phenotypic changes in response to the rust pathogen. Knocking outTa7ANPR1 enhanced resistance to stem rust. TheTa7ANPR1 locus is alternatively spliced under pathogen inoculated conditions.Ta7ANPR1 locus through an NB‐ARC–NPR1 fusion protein negatively regulating the defence to stem rust infection. -
Salicylic acid (SA) is a plant defense signal that mediates local and systemic immune responses against pathogen invasion. However, the underlying mechanism of SA-mediated defense is very complex due to the involvement of various positive and negative regulators to fine-tune its signaling in diverse pathosystems. Upon pathogen infections, elevated level of SA promotes massive transcriptional reprogramming in which Non-expresser of PR genes 1 (NPR1) acts as a central hub and transcriptional coactivator in defense responses. Recent findings show that Enhanced Disease Susceptibility 1 (EDS1) also functions as a transcriptional coactivator and stimulates the expression of PR1 in the presence of NPR1 and SA. Furthermore, EDS1 stabilizes NPR1 protein level, while NPR1 sustains EDS1 expression during pathogenic infection. The interaction of NPR1 and EDS1 coactivators initiates transcriptional reprogramming by recruiting cyclin-dependent kinase 8 in the Mediator complex to control immune responses. In this review, we highlight the recent breakthroughs that considerably advance our understanding on how transcriptional coactivators interact with their functional partners to trigger distinct pathways to facilitate immune responses, and how SA accumulation induces dynamic changes in NPR1 structure for transcriptional reprogramming. In addition, the functions of different Mediator subunits in SA-mediated plant immunity are also discussed in light of recent discoveries. Taken together, the available evidence suggests that transcriptional coactivators are essential and potent regulators of plant defense pathways and play crucial roles in coordinating plant immune responses during plant–pathogen interactions.more » « less
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