AUTHOR=Kubra Ghulam , Khan Maryam , Munir Faiza , Gul Alvina , Shah Tariq , Hussain Adil , Caparrós-Ruiz David , Amir Rabia 

TITLE=Expression Characterization of Flavonoid Biosynthetic Pathway Genes and Transcription Factors in Peanut Under Water Deficit Conditions

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.680368

DOI=10.3389/fpls.2021.680368

ISSN=1664-462X

ABSTRACT=<p>Drought is one of the hostile environmental stresses that limit the yield production of crop plants by modulating their growth and development. Peanut (<italic>Arachis hypogaea</italic>) has a wide range of adaptations to arid and semi-arid climates, but its yield is prone to loss due to drought. Other than beneficial fatty acids and micronutrients, peanut harbors various bioactive compounds including flavonoids that hold a prominent position as antioxidants in plants and protect them from oxidative stress. In this study, understanding of the biosynthesis of flavonoids in peanut under water deficit conditions was developed through expression analysis and correlational analysis and determining the accumulation pattern of phenols, flavonols, and anthocyanins. Six peanut varieties (BARD479, BARI2011, BARI2000, GOLDEN, PG1102, and PG1265) having variable responses against drought stress have been selected. Higher water retention and flavonoid accumulation have been observed in BARI2011 but downregulation has been observed in the expression of genes and transcription factors (TFs) which indicated the maintenance of normal homeostasis. ANOVA revealed that the expression of flavonoid genes and TFs is highly dependent upon the genotype of peanut in a spatiotemporal manner. Correlation analysis between expression of flavonoid biosynthetic genes and TFs indicated the role of <italic>AhMYB111</italic> and <italic>AhMYB7</italic> as an inhibitor for <italic>AhF3H</italic> and <italic>AhFLS</italic>, respectively, and <italic>AhMYB7, AhTTG1</italic>, and <italic>AhCSU2</italic> as a positive regulator for the expression of <italic>Ah4CL, AhCHS, and AhF3H</italic>, respectively. However, <italic>AhbHLH</italic> and <italic>AhGL3</italic> revealed nil-to-little relation with the expression of flavonoid biosynthetic pathway genes. Correlational analysis between the expression of TFs related to the biosynthesis of flavonoids and the accumulation of phenolics, flavonols, and anthocyanins indicated coregulation of flavonoid synthesis by TFs under water deficit conditions in peanut. This study would provide insight into the role of flavonoid biosynthetic pathway in drought response in peanut and would aid to develop drought-tolerant varieties of peanut.</p>