ERF Transcription Factor OsBIERF3 Positively Contributes to Immunity against Fungal and Bacterial Diseases but Negatively Regulates Cold Tolerance in Rice.

Yongbo Hong,Jiajing Wang,Yuqing Yan,Xiaohui Xiong,Fengming Song,Yan Bi,Hui Wang,Dayong Li,Yizhou Gao

doi:10.3390/ijms23020606

Abstract

We previously showed that overexpression of the rice ERF transcription factor gene OsBIERF3 in tobacco increased resistance against different pathogens. Here, we report the function of OsBIERF3 in rice immunity and abiotic stress tolerance. Expression of OsBIERF3 was induced by Xanthomonas oryzae pv. oryzae, hormones (e.g., salicylic acid, methyl jasmonate, 1-aminocyclopropane-1-carboxylic acid, and abscisic acid), and abiotic stress (e.g., drought, salt and cold stress). OsBIERF3 has transcriptional activation activity that depends on its C-terminal region. The OsBIERF3-overexpressing (OsBIERF3-OE) plants exhibited increased resistance while OsBIERF3-suppressed (OsBIERF3-Ri) plants displayed decreased resistance to Magnaporthe oryzae and X. oryzae pv. oryzae. A set of genes including those for PRs and MAPK kinases were up-regulated in OsBIERF3-OE plants. Cell wall biosynthetic enzyme genes were up-regulated in OsBIERF3-OE plants but down-regulated in OsBIERF3-Ri plants; accordingly, cell walls became thicker in OsBIERF3-OE plants but thinner in OsBIERF3-Ri plants than WT plants. The OsBIERF3-OE plants attenuated while OsBIERF3-Ri plants enhanced cold tolerance, accompanied by altered expression of cold-responsive genes and proline accumulation. Exogenous abscisic acid and 1-aminocyclopropane-1-carboxylic acid, a precursor of ethylene biosynthesis, restored the attenuated cold tolerance in OsBIERF3-OE plants while exogenous AgNO3, an inhibitor of ethylene action, significantly suppressed the enhanced cold tolerance in OsBIERF3-Ri plants. These data demonstrate that OsBIERF3 positively contributes to immunity against M. oryzae and X. oryzae pv. oryzae but negatively regulates cold stress tolerance in rice.

Highlights

As sessile organisms, plants are unable to escape from unfavorable environments and often suffer from numerous abioticand biotic stresses
We previously observed that OsBIERF3 was induced by benzothiadiazole, an analog of salicylic acid (SA), and by M. oryzae [46]
We further examined the responsiveness of OsBIERF3 in response to X. oryzae pv. oryzae by analyzing the transcript levels in the incompatible and compatible interactions between a pair of rice near-isogenic lines IR24 and BB10 and X. oryzae pv. oryzae

Summary

Introduction

Plants are unable to escape from unfavorable environments and often suffer from numerous abiotic (drought, salt, extreme temperature, etc.)and biotic (pathogens, herbivore insects, etc.) stresses. Upon perception of external stress signals, complicated hormone-mediated signaling networks are often activated in effective and timely manners [7–11], which lead to transcriptional reprogramming that coordinately regulates the expression of a large set of genes to initiate stress responses [12–15]. This large-scale transcriptional reprogramming of gene expression in a specific stress response requires the concerted action of chromatin dynamics and different types of transcription factors (TFs) in both temporal and spatial manners [15–20]. ERFs have been shown to participate in diverse biological processes including plant growth and development, immunity, and abiotic stress tolerance [22,27,28,38–42] and provide promising potential in the improvement of biotic and abiotic stress tolerance in crop plants [43–45]

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Results

Conclusion