Distinct Preflowering Drought Tolerance Strategies of Sorghum bicolor Genotype RTx430 Revealed by Subcellular Protein Profiling

• Published in: International journal of molecular sciences 2020-12, Vol.21 (24), p.9706
• Main Authors: Ogden, Aaron J, Abdali, Shadan, Engbrecht, Kristin M, Zhou, Mowei, Handakumbura, Pubudu P
• Format: Article
• Language: English
• Subjects: abiotic stress; Abscisic acid; Adaptation; adaptive mechanisms; BASIC BIOLOGICAL SCIENCES; Biosynthesis; Drought; Drought resistance; drought stress; drought tolerance; Droughts; Experiments; Flowering; FLOWERING LOCUS C; Flowers - genetics; Flowers - physiology; Gene expression; Gene Expression Regulation, Plant; Genotype; Genotype & phenotype; Genotypes; Heat shock proteins; Organelles; Plant Proteins - metabolism; postflowering; preflowering; Principal components analysis; Proteome - analysis; Proteome - metabolism; proteomics; Reactive oxygen species; Ribulose-bisphosphate carboxylase; rubisco activase; Scavenging; Signal transduction; Sorghum; Sorghum - genetics; Sorghum - physiology; Sorghum bicolor; Stress, Physiological; Subcellular Fractions - metabolism; Water stress
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21249706

Drought is the largest stress affecting agricultural crops, resulting in substantial reductions in yield. Plant adaptation to water stress is a complex trait involving changes in hormone signaling, physiology, and morphology. Sorghum ( (L.) Moench) is a C4 cereal grass; it is an agricultural staple, and it is particularly drought-tolerant. To better understand drought adaptation strategies, we compared the cytosolic- and organelle-enriched protein profiles of leaves from two genotypes, RTx430 and BTx642, with differing preflowering drought tolerances after 8 weeks of growth under water limitation in the field. In agreement with previous findings, we observed significant drought-induced changes in the abundance of multiple heat shock proteins and dehydrins in both genotypes. Interestingly, our data suggest a larger genotype-specific drought response in protein profiles of organelles, while cytosolic responses are largely similar between genotypes. Organelle-enriched proteins whose abundance significantly changed exclusively in the preflowering drought-tolerant genotype RTx430 upon drought stress suggest multiple mechanisms of drought tolerance. These include an RTx430-specific change in proteins associated with ABA metabolism and signal transduction, Rubisco activation, reactive oxygen species scavenging, flowering time regulation, and epicuticular wax production. We discuss the current understanding of these processes in relation to drought tolerance and their potential implications.