Physiological and metabolic responses of Jatropha to chilling stress
2013
Gao, J. (Sichuan Univ., Chengdu (China). Coll. of Life Sciences) | Jiang, N. (Sichuan Univ., Chengdu (China). Coll. of Life Sciences) | Qin, X. (Sichuan Academy of Natural Resource Sciences, Chengdu (China)) | Zhu, X. | Ai, T. | Peng, T. | Wu, J. | Wu, J. | Xu, Y. | Chen, F.
Chilling susceptibility is the bottleneck for cultivation and commercialization of Jatropha curcas L., a novel promising biodiesel tree. To explore its network reactions to cold stress and pick out the most valuable approach for germplasm improvement, four pop systems, consisting of reactive oxygen species (ROS) scavenging enzymes, photosystem, glycol-metabolism and phenylpropanoid metabolism, and typical chilling-induced genes/transcription factors (TFs) were detected in seedlings exposed to 4 degree C. The results revealed that J. curcas has high cold-sensitivity might result from its seriously hysteretic responses (at least 2-3 h delay) to chilling damages. Among its molecular web of cold response, CBF TFs reacted most dramatically, up to 44-118 folds above the control. High chilling-responsiveness indicated CBFs should be candidates of gene engineering for improvement of chilling tolerance in J. curcas. Results also revealed that glycolysis, tricarboxylic acid and hexose monophosphate pathways might generate more ATP, NADH/NADPH for photosystem to maintain the cyclic electron flow. Besides the ROS scavenging system, flavonoids from phenylpropanoid pathway could also protect membrane lipid in cold stress. The studies provided a foundational knowledge of net response of J. curcas to chilling stress, and inspired that predictable and rapid response of CBF regulon is the direction for improvement of cold tolerance.
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