Transcriptomic and metabolomic profiles reveal integrative mechanisms underlying the drought tolerance in Rosa banksiae petals

Abstract Drought stress induces premature wilting and accelerates petal senescence, thereby diminishing the commercial value of roses. Rosa banksiae , renowned for its drought tolerance, serves as an optimal model for investigating drought-responsive mechanisms within the genus Rosa . In this study, a comparative analysis was conducted to evaluate the drought tolerance of petals from R. banksiae f. lutea (RbY) and R. banksiae var. banksiae (RbW) under treatment with 20% polyethylene glycol 6000. Physiological assessments demonstrated that RbY exhibited superior drought tolerance relative to RbW. Integrated transcriptomic and metabolomic analyses identified several drought-responsive pathways common to both genotypes, including isoflavonoid biosynthesis, glutathione metabolism, and betaine biosynthesis. Remarkably, pathways associated with flavonoid and coumarin biosynthesis, glutathione metabolism, betaine biosynthesis, and phytohormone signaling were implicated as major contributors to RbY’s enhanced dehydration tolerance. These pathways corresponded with elevated levels of metabolites such as γ-glutamylcysteine, celosianin II, 2''-(6''-p-coumaroylglucosyl) quercitrin, imperatorin, and jasmonic acid-isoleucine. Subsequent quantitative real-time polymerase chain reaction validation revealed that key genes within these pathways, including cinnamate 4-hydroxylase ( C4H ), chalcone synthase ( CHS ), chalcone isomerase ( CHI ) , phospholipase A1 ( LCAT3 ), allene oxide synthase ( AOS ), ascorbate peroxidase ( APX ), and glutathione S-transferase ( GSTs ), may underlie the intensified drought response observed in RbY. Collectively, the findings suggest that the superior drought tolerance of RbY is orchestrated through a coordinated defense system involving antioxidative mechanisms, hormonal regulation, and osmotic adjustment. These insights provide valuable knowledge for elucidating the molecular underpinnings of drought adaptation in rose petals and establish a foundation for breeding drought-resilient rose cultivars.