Plant height shapes hydraulic architecture but does not predict metaxylem area under drought in Sorghum bicolor

Abstract

Climate change-induced variations in temperature and precipitation negatively impact plant growth and development. To ensure future food quality and availability, a critical need exists to identify morphological and physiological responses that confer drought tolerance in agro-economically important crop plants throughout all growth stages. In this study, two Sorghum bicolor accessions that differ in their preflowering responses to drought were exposed to repeated cycles of drying and rewatering. Morphological, physiological, and histological traits were measured across both juvenile and adult developmental stages. Our results demonstrate that plant height is not predictive of metaxylem area but does influence the hydraulic path and water management in an accession-specific manner. Further, when droughtresponsive changes to the plant architecture are unable to compensate for the hydraulic risk associated with prolonged drought exposure, tight control of stomatal aperture is crucial to further mitigate hydraulic damage and prevent xylem embolism.

The Over-Expression of Two R2R3-MYB Genes, PdMYB2R089 and PdMYB2R151, Increases the Drought-Resistant Capacity of Transgenic Arabidopsis

“…In addition to natural aging, drought and drought-induced pests or diseases are considered to be important external factors that accelerate tree death [1,2]. Plants respond to water deficit by changing their morphological architecture, expressing drought-resistant genes, and synthesizing osmoregulation substances and phytohormones [3][4][5][6]. Transcription factors (TFs), as potential candidate genes in drought-tolerant breeding, play an essential regulating role in plant response to drought stress [7][8][9].…”