Dehydration response in Stylosanthesscabra: transcriptional, biochemical, and physiological modulations.

tylosanthes scabra, popularly known as stylo, is native to the Brazilian Caatinga semi-arid region and stands out as a drought-tolerant shrub forage crop. This work pro-vides information about the plant response during the first 48 h of water deficit,followed by a rehydration treatment. Besides root transcriptomics data, 13 physiolog-ical or biochemical parameters were scrutinized. Additionally, RNA-Seq annotatedtranscripts not associated with the?Viridiplantae?clade were taxonomically catego-rized. It was found thatS. scabraquickly perceives and recovers from the oscillationsof the imposed water regime. Physiologically, mechanisms that minimize evapotrans-piration or protect the photosynthetic apparatus stood out. Biochemically, it wasfound that the root tissue invests in synthesizing compounds that can act as osmo-lytes (proline and sugars), emphasizing the importance of osmoregulation to waterdeficit acclimation. Consistently, transcriptome and qPCR analyses showed that a setof enriched biological processes with upregulated (UR) transcripts were involved inprotective functions against reactive oxygen species or encoding enzymes of impor-tant metabolic pathways, which might contribute toS. scabraresponse to water defi-cit. Additionally, several UR kinases and transcription factors were identified. Finally,in an innovative approach, some naturally occurring microbial groups (such asSchizo-saccharomyces,Bradyrhizobium, etc.) were identified in theS. scabraroots. This studyreveals insights into the physiological, biochemical, and molecular mechanisms under-lying theS. scabraresponse to water deficit and provides candidate genes that maybe useful in developing drought-tolerant crop varieties through biotechnologicalapplications