The Expression of Genes Involved in Phenylpropanoid Biosynthesis Correlates Positively with Phenolic Content and Antioxidant Capacity in Developing Chickpea (Cicer arietinum L.) Seeds

Chickpea (<i>Cicer arietinum</i> L.) seeds have a great diversity of phenolic compounds and antioxidant capacity, which is associated with the regulation of the phenylpropanoid pathway. We investigated this association in developing seeds (20 and 30 days after anthesis, DAA) from six chickpea genotypes (two kabuli and four desi). They were used to evaluate total phenolics (TP), total flavonoids (TF), phenolic composition, antioxidant capacity (AC), and the relative expression of MYB transcription factors (<i>CaMYB39</i>, <i>MYB111-like</i>, and <i>CaMYB92</i>) and phenylpropanoid biosynthetic genes (<i>PAL</i>, <i>CHI</i>, and <i>CHS</i>). TP, TF, and the AC increased significantly during seed development, and the highest values were observed in desi genotypes. The AC correlated with the levels of TP, TF, and the flavonols myricetin, quercetin, kaempferol, and isorhamnetin. The levels of the phenolic compounds and the AC also correlated positively with the expression of MYB transcription factors and phenylpropanoid biosynthetic genes. The expression of <i>CaMYB39</i> correlated significantly with that of <i>PAL</i>, <i>CHS</i>, and <i>CHI</i>, indicating the potential use of this MYB factor to improve the content of phenylpropanoids. The desi genotype with black seeds (ICC 4418) showed the highest levels of gene expression, TP, TF, and AC, suggesting it can be used to produce chickpeas with enhanced nutraceutical properties.