Gene Expression Correlation Analysis Reveals MYC-NAC Regulatory Network in Cotton Pigment Gland Development.

Hailiang Cheng,Da Qu,Yuanli Dai,Limin Lv,Shang Liu,Man He,Qiaolian Wang,Shuyan Li,Dongyun Zuo,Guoli Song,Chaofeng Wu,Youping Zhang,Xiaoxu Feng

doi:10.3390/ijms22095007

Abstract

Plant NAC (NAM, ATAF1/2, and CUC2) family is involved in various development processes including Programmed Cell Death (PCD) associated development. However, the relationship between NAC family and PCD-associated cotton pigment gland development is largely unknown. In this study, we identified 150, 153 and 299 NAC genes in newly updated genome sequences of G. arboreum, G. raimondii and G. hirsutum, respectively. All NAC genes were divided into 8 groups by the phylogenetic analysis and most of them were conserved during cotton evolution. Using the vital regulator of gland formation GhMYC2-like as bait, expression correlation analysis screened out 6 NAC genes which were low-expressed in glandless cotton and high-expressed in glanded cotton. These 6 NAC genes acted downstream of GhMYC2-like and were induced by MeJA. Silencing CGF1 (Cotton Gland Formation1), another MYC-coding gene, caused almost glandless phenotype and down-regulated expression of GhMYC2-like and the 6 NAC genes, indicating a MYC-NAC regulatory network in gland development. In addition, predicted regulatory mechanism showed that the 6 NAC genes were possibly regulated by light, various phytohormones and transcription factors as well as miRNAs. The interaction network and DNA binding sites of the 6 NAC transcription factors were also predicted. These results laid the foundation for further study of gland-related genes and gland development regulatory network.

Highlights

Cotton is an important economic crop providing natural fiber resource and potential nutrition resource
Total 299, 150 and 153 NAC proteins were obtained in G. hirsutum, G. arboreum and G. raimondii respectively using hmmsearch and blastp search
Athmeo6nNgAoCf sthfuemnc,tGiohn_eNdAdCo8w5nasntrdeaGmh_oNf AGChM23Y5Cw2e-lriekehaignhdeJsAt sseignnsiatilvinegtpoaMthewJAaytrmeaigtmhtebnet ainvdoslhvoedweindgalbaonudtd1e5vteilmopesmoefnet.xpression level at peak than 0 h stage. These results suggested the 6 NACs functioned downstream of GhMYC2-like and JA signaling pathway might be involved in gland development

Summary

Introduction

Cotton is an important economic crop providing natural fiber resource and potential nutrition resource. Global cottonseed production, if being fully utilized, could provide sufficient protein consumption for 500 million people one year [1]. Presence of toxic gossypol in pigment gland limited the use of the cottonseed production due to its toxicity for human and monogastric animals [2,3]. Gossypol is phytoalexin providing plant resistance to various insects and pathogens [4,5,6,7]. It is significant for improving cotton economic value to breed cotton cultivars with high gossypol in plant and low gossypol in seed. The transgenic cotton showed reduced gossypol content in seed and normal in foliage and floral parts [10,12]

Methods

Results

Conclusion