Barley strigolactone signalling mutant hvd14.d reveals the role of strigolactones in abscisic acid‐dependent response to drought

Abstract

Strigolactones (SLs) are a group of plant hormones involved in many aspects of plant development and stress adaptation. Here, we investigated the drought response of a barley (Hordeum vulgare L.) mutant carrying a missense mutation in the gene encoding the SL-specific receptor HvD14. Our results clearly showed that hvd14.d mutant is hyper-sensitive to drought stress. This was illustrated by a lower leaf relative water content (RWC), impaired photosynthesis, disorganization of chloroplast structure, altered stomatal density and slower closure of stomata in response to drought in the mutant compared to the wild type parent cultivar Sebastian. Although the content of abscisic acid (ABA) and its derivatives remained unchanged in the mutant, significant differences in expression of genes related to ABA biosynthesis were observed. Moreover, hvd14.d was insensitive to ABA during seed germination. Analysis of Arabidopsis thaliana mutant atd14-1 also demonstrated that mutation in the SL receptor resulted in increased sensitivity to drought. Our results indicate that the drought-sensitive phenotype of barley SL mutant might be caused by a disturbed ABA metabolism and/or signalling pathways. These results together uncovered a link between SL signalling and ABA-dependent drought stress response in barley.

Diverse Roles of MAX1 Homologues in Rice

“…This observation is in agreement with results obtained for TFs that regulate expression of Os06g0565100, including OsWR1, which promotes the expression of genes involved in wax synthesis. There is increasing evidence that SLs are involved in plant response to drought [205][206][207] and one of the components of plant responses to drought is deposition of waxes. Thus, it can be proposed that one of the MAX1 homologue plays a role in wax biosynthesis and deposition, which may help plants to adapt to drought conditions.…”

Effects of exogenous Strigolactone on the physiological and ecological characteristics of Pennisetum purpureum Schum. Seedlings under drought stress

“…The interactions among SL, growth hormone, ABA, and other plant hormones jointly regulate abiotic stresses. In particular, the interaction between SL and ABA is the key to abiotic stress tolerance [ 63 , 64 ]. The interaction between SL and ABA plays an important role in integrating stress signals and regulating stomatal development and function.…”

Effects of Exogenous Strigolactone on the Physiological and Ecological Characteristics of Pennisetum Purpureum Schum. Seedlings under Drought Stress

“…ABA accumulates rapidly under saline and drought conditions and is considered to be a "stress hormone" (Hong et al 2013;Lim et al 2015). The interactions between SLs, growth hormone, ABA, and other plant hormones jointly regulate abiotic stresses; most especially, the interaction between SLs and ABA is the key to abiotic stress tolerance (Marzec et al 2020;Liu et al 2015). The interaction between SLs and ABA plays an important role in integrating stress signals and regulating stomatal development and function.…”