Regulation and physiological function of proteins for heat tolerance in cowpea (Vigna unguiculata) genotypes under controlled and field conditions

• Published in: Frontiers in plant science Vol. 13; p. 954527
• Main Authors: Selinga, Tonny I., Maseko, Sipho T., Gabier, Hawwa, Rafudeen, Mohammed S., Muasya, A. Muthama, Crespo, Olivier, Ogola, John B. O., Valentine, Alex J., Ottosen, Carl-Otto, Rosenqvist, Eva, Chimphango, Samson B. M.
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 22.08.2022
• Subjects: cowpea; heat shock proteins; label-free protein quantification; plant proteomics; Plant Science; thermotolerance mechanisms
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2022.954527

The expression of heat shock proteins is considered a central adaptive mechanism to heat stress. This study investigated the expression of heat shock proteins (HSPs) and other stress-protective proteins against heat stress in cowpea genotypes under field (IT-96D-610 and IT-16) and controlled (IT-96D-610) conditions. Heat stress response analysis of proteins at 72 h in the controlled environment showed 270 differentially regulated proteins identified using label-free quantitative proteomics in IT-96D-610 plants. These plants expressed HSPs and chaperones [BAG family molecular chaperone 6 (BAG6), Multiprotein bridging factor1c (MBF1C) and cold shock domain protein 1 (CSDP1) in the controlled environment]. However, IT-96D-610 plants expressed a wider variety of small HSPs and more HSPs in the field. IT-96D-610 plants also responded to heat stress by exclusively expressing chaperones [DnaJ chaperones, universal stress protein and heat shock binding protein (HSBP)] and non-HSP proteins (Deg1, EGY3, ROS protective proteins, temperature-induced lipocalin and succinic dehydrogenase). Photosynthesis recovery and induction of proteins related to photosynthesis were better in IT-96D-610 because of the concurrent induction of heat stress response proteins for chaperone functions, protein degradation for repair and ROS scavenging proteins and PSII operating efficiency (Fq’/Fm′) than IT-16. This study contributes to identification of thermotolerance mechanisms in cowpea that can be useful in knowledge-based crop improvement.