Overexpression of a major latex-like protein from wild Arachis (AdMLP11) confers tolerance to recurrent drought stress.

Recurrent drought episodes, increasingly intensified by climate change, pose a growing threat to global food security by severely limiting crop productivity. Major latex-like proteins (MLPs) play crucial roles in drought tolerance, acting as regulators of stress responses. However, their involvement in adaptation to recurrent drought stress remains poorly understood. In this study, we investigated the transcriptional dynamics of MLP genes during repeated dehydration and rehydration cycles in Arachis duranensis, a tropical wild species highly resilient to drought. In silico expression profiling of 36 A. duranensis MLP genes revealed their broad involvement in recurrent drought responses, with most patterns consistent with the 'revised-response' category of dehydration memory genes. qRT-PCR analysis further confirmed the activation of the abscisic acid (ABA) signaling pathway during recurrent drought in A. duranensis. Functional characterization of the candidate memory gene AdMLP11 in transgenic tobacco showed that its overexpression enhances tolerance to moderate and severe recurrent drought, likely through its role as a positive regulator of phytohormone-mediated defense pathways. These findings provide novel insights into the role of MLPs in transcriptional memory and drought adaptation in wild Arachis, highlighting AdMLP11 as a promising target for biotechnological strategies to develop climate-resilient crops.