Expression and Function Analysis of a <i>MiNAC7</i> Gene in Response to Flowering and Abiotic Stress in Mango
Welcome to Chinese Journal of Tropical Crops,

Chinese Journal of Tropical Crops ›› 2023, Vol. 44 ›› Issue (11): 2256-2264.DOI: 10.3969/j.issn.1000-2561.2023.11.014

• Omics & Biotechnology • Previous Articles     Next Articles

Expression and Function Analysis of a MiNAC7 Gene in Response to Flowering and Abiotic Stress in Mango

HUANG Xing, XU Huanhuan, LI Kaijiang, HE Xinhua*(), XIA Liming, LU Tingting, LIANG Rongzhen, LUO Cong*()   

  1. College of Agriculture, Guangxi University / State Key Laboratory for Protection and Utilization of Subtropical Agricultural Biological Resources / Guangxi Key Laboratory for Agro-Environment and Agro-Product Safety, Nanning, Guangxi 530004, China
  • Received:2022-09-30 Revised:2022-11-04 Online:2023-11-25 Published:2023-12-08
  • Contact: *HE Xinhua,E-mail:honest66222@163.com;LUO Cong,E-mail:22003luocong@163.com

Abstract:

NAC transcription factors are a large gene family in plants which play important roles in regulating plant growth and development, signal transduction, stress response, etc. In the previous study, the NAC gene, named MiNAC7, was isolated by the yeast two-hybrid system. In this study, the bioinformatics, expression patterns and gene functions of genes were studied. Bioinformatics analysis showed that the MiNAC7 gene was located on chromosome 10, with 4 introns and 5 exons. The length of the coding region of the MiNAC7 gene was 1137 bp, encoding 379 amino acids, the theoretical isoelectric point was 4.88, the molecular weight of the protein was 93.41 kDa, and the amino acid sequence contained a conserved NAM domain. Phylogenetic tree analysis showed that mango MiNAC7 and pistachio PvNAC26 had the closest genetic relationship and the highest homology, and the amino acid sequence similarity was 69.64%. Promoter sequence analysis showed that the promoter region of the MiNAC7 gene contained light response elements, gibberellin response elements and auxin response elements. Expression analysis showed that the expression level of the MiNAC7 gene was high in the stems and buds of juvenile tissues, low in flowers, high in the stems of adult tissues, and low in flowers and leaves. At the same time, it was found that the MiNAC7 gene maintained a high expression level in the leaves at the vegetative growth stage and a low expression level in the leaves at the flowering transformation stage and flower development stage. Overexpression of the MiNAC7 gene led to a late-flowering phenotype in transgenic Arabidopsis. The overexpression of the MiNAC7 gene in Arabidopsis significantly reduced the expression level of the floral-promoting genes AtFT and AtAP1, while the expression level of the late-flowering gene AtFLC was significantly increased. Stress treatment showed that Arabidopsis with excessive expression of the MiNAC7 gene improved its resistance to drought and salt and improved its resistance to GA3 but was more sensitive to ABA. This study shows that the mango MiNAC7 gene not only affects flowering but also participates in the response to abiotic stress, which would lay a foundation for further research on the gene regulatory network of the MiNAC7 gene involved in regulating mango flowering and stress response.

Key words: mango, MiNAC7, bioinformatics analysis, expression pattern, functional research

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