Physiological Mechanisms Involved with Salt and Drought Tolerance in Jatropha curcas Plants
Although the importance ofJ. curcasplants as a bioenergy source is well recognized, the key physiological processes involved in drought and salt tolerance are poorly known. The geographical distribution ofJ. curcasstrongly suggests that this species is drought tolerant. However, the features of the physiological parameters of drought tolerance were based, until now, on a narrow genetic basis that was not well characterized. In the tropical, semi-arid regions where the cultivation ofJ. curcasis increasing, problems of primary salinity and secondary salinization caused by irrigation can be critical. In this review, we present recent results regarding the most important physiological processes related to drought and salt tolerance inJ. curcas,including osmotic adjustment, photosynthesis and oxidative protection. Overall, the data reported suggest thatJ. curcashas both biochemical and physiological characteristics that confer drought tolerance and relative salt sensitivity during its initial growth phase. The possibility of sustainable production ofJ. curcaswithout irrigation in semiarid regions is controversial, partly because the physiology of this species is not yet sufficiently known and the plant breeding has presented little progress. In addition, the development of “evergreen crops” with irrigation also requires physiological studies and genotypes that respond adequately to water investment under adverse conditions of high temperature and salinity.
KeywordsBiomass Sugar Toxicity Sucrose Chlorophyll
The authors would like to thank the Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico (FUNCAP) and Fundação Cearence de Pesquisa e Cultura (FCPC) for financial support (Project 2155/Programa Núcleos de Excelência, PRONEX) and the Fazenda Tamanduá for supplying theJatropha curcasseeds.
- Chaves MM, Flexas J, Pinheiro C (2008) Photosynthesis under drought and salt stress: regulation mechanisms from whole plant to cell. Ann Bot 125:1–10Google Scholar
- Díaz-López L, Gimeno V, Simón I, Martínez V, Rodríguez-Ortega WM, García-Sanchez F (2012) Jatropha curcas seedlings show a water conservation strategy under drought conditions based on decreasing leaf growth and stomatal conductance. Agric Water Manag 105:48–56. doi: 10.1016/j.agwat.2012.01.001 CrossRefGoogle Scholar
- Flexas J, Ribas-Carbó M, Bota J, Galmés J, Henkle M, Martinez-Canellas S et al (2006) Decreased Rubisco activity during water stress is not induced by decreased relative water content but related to condition of low stomatal conductance and chloroplast CO2concentration. New Phytol 172:73–82PubMedCrossRefGoogle Scholar
- Rodrigues CRF, Silva EN, Dutra ATB, Viégas RA, Silveira JAG (2012) Transport and partitioning of K+alleviates toxic effects of Na+ions inJatropha curcasyoung plants. Rev Bras Ciên Solo. in pressGoogle Scholar
- Silva EN, Silveira JAG, Fernandes CRR, Dutra ATB, Aragão RM (2009a) Ion uptake and growth ofJatrophaunder different salinity levels. Rev Ciên Agron 40:240–246Google Scholar
- Yeo A (1998) Molecular biology of salt tolerance in the context of whole-plant physiology. J Exp Bot 49:915–929Google Scholar