title: Root proteomic responses to heat stress in two Agrostis grass species contrasting in heat tolerance.
abstract: Protein metabolism plays an important role in plant adaptation to heat stress. This study was designed to identify heat-responsive proteins in roots associated with thermotolerance for two C3 grass species contrasting in heat tolerance, thermal Agrostis scabra and heat-sensitive Agrostis stolonifera L. Plants were exposed to 20 degrees C (control), 30 C (moderate heat stress), or 40 degrees C (severe heat stress) in growth chambers. Roots were harvested at 2 d and 10 d after temperature treatment. Proteins were extracted and separated by two-dimensional polyacrylamide gel electrophoresis. Seventy protein spots were regulated by heat stress in at least one species. Under both moderate and severe heat stress, more proteins were down-regulated than were up-regulated, and thermal A. scabra roots had more up-regulated proteins than A. stolonifera roots. The sequences of 66 differentially expressed protein spots were identified using mass spectrometry. The results suggested that the up-regulation of sucrose synthase, glutathione S-transferase, superoxide dismutase, and heat shock protein Sti (stress-inducible protein) may contribute to the superior root thermotolerance of A. scabra. In addition, phosphoproteomic analysis indicated that two isoforms of fructose-biphosphate aldolase were highly phosphorylated under heat stress, and thermal A. scabra had greater phosphorylation than A. stolonifera, suggesting that the aldolase phosphorylation might be involved in root thermotolerance.
authors.affiliation: Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ 08901, USA.
authors.forename: Chenping
authors.initials: C
authors.lastname: Xu
authors.forename: Bingru
authors.initials: B
authors.lastname: Huang
mesh_terms: D031703:Agrostis / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D015180:Electrophoresis, Gel, Two-Dimensional; D006358:Hot Temperature; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D040901:Proteomics
chemical_list: D010940:Plant Proteins