Work

Functional characterization reveals MiNAC25 and MiSGR1 as key regulators of chlorophyll degradation in mango

Year: 2026

Type: article

Abstract: Chlorophyll degradation is crucial for fruit ripening and coloration, but its transcriptional regulation in mango ( Mangifera indica L.) remains unclear. Here, we investigated two mango cultivars, ‘Guire 82’ (persistent green) and ‘Neelum’ (yellowing), and integrated metabolomic and transcriptomic analyses implicated porphyrin and chlorophyll metabolism as the central pathway underlying peel color divergence. Weighted gene co-expression network analysis (WGCNA) identified key modules linked to pigmentation, from which we uncovered that a NAC-family transcription factor MiNAC25 as a central regulator within the chlorophyll degradation network. MiSGR1 a key chlorophyll catabolic gene, showed co-expression with MiNAC25, and in silico analysis revealed potential NAC-binding sites in its promoter. Subcellular localization confirmed the nuclear localization of MiNAC25 and the chloroplast localization of MiSGR1 . Functional validation in tomato demonstrated that heterologous overexpression of either MiNAC25 or MiSGR1 significantly accelerated chlorophyll degradation and up-regulated the expression of endogenous chlorophyll catabolic genes ( SlPPH , SlPAO , SlRCCR ). Notably, MiNAC25 overexpression also activated the tomato SGR ortholog. Our findings reveal a previously uncharacterized transcriptional module in which the nuclear MiNAC25 potentially coordinates chlorophyll breakdown, possibly through influencing MiSGR1 and other catabolic genes, to govern peel yellowing in mango. This study provides key insights into the regulatory mechanism of fruit coloration and identifies MiNAC25 and MiSGR1 as strategic targets for improving mango fruit quality. • Integrated multi-omics analysis identifies chlorophyll metabolism as the central pathway for peel color divergence between the persistent-green ‘Guire 82’ and the yellowing ‘Neelum’ mango. • MiNAC25 is identified as a hub NAC transcription factor within a co-expression network highly associated with chlorophyll degradation. • Functional validation in tomato confirms that heterologous overexpression of either MiNAC25 or MiSGR1 accelerates chlorophyll breakdown and upregulates endogenous catabolic genes. • A potential regulatory link is suggested, as MiNAC25 overexpression activates the tomato SGR ortholog, and its promoter contains putative NAC-binding sites.

Source: Plant Physiology and Biochemistry

DOI: 10.1016/j.plaphy.2026.111095

Authors: Xiao Du, Xueyu Cui, Wenping Zeng, Yujiao Peng, Qianfu Chen, Yerong Wang

Institutions: Nanning Normal University, Baise University

Language: English

Topic: Plant Gene Expression Analysis

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Zero hunger

Open Access status: hybrid

Estimated APC paid: $3,990