Decoding Hayward Kiwi (Actinidia deliciosa var Hayward) Genome: Transcriptomic Responses to Drought and Salinity and AdhSAP4s Role in Salinity Stress Response
Plants, as sessile organisms, must adapt to various environmental stressors, particularly high salinity and water scarcity. To mitigate these challenges, plants activate molecular signaling cascades that reorganize cellular processes to minimize oxidative damage. Plant responses to stress include both positive and negative regulators that balance defense mechanisms and normal cellular function. In this study, we focus on the kiwi (Actinidia deliciosa, var. Hayward), a specie sensitive to drought and salinity. We performed genomic analysis generating a genome sequence with 42,797 annotated protein-coding genes, covering 44.61% of the genome, and 96.2% BUSCO completeness. Using RNA-Seq analysis, we identified genes differentially expressed in response to acute (6 and 12 hours) drought and salinity stress. Notably, the AdhSAP4 gene was identified as a potential negative regulator of stress response. AdhSAP4 belongs to a novel family of proteins known as stress-associated proteins (SAPs) that have been implicated in plant tolerance to various abiotic stresses. Functional analysis in Nicotiana tabacum revealed that overexpression of AdhSAP4 increased sensitivity to salt stress, indicating its role as a negative regulator to salinity in plants. This work provides insights into the molecular mechanisms underlying kiwi's response to abiotic stress and highlights the potential of SAP family proteins in regulating plant stress tolerance.