ABSTRACT
Dry land systems spread all over the world and comprise 41.3% of the terrestrial area, which host 34.7% of the global population, so it is convenient to propose crops able to grow there. Jatropha curcas is a plant adapted to arid and semiarid regions as well as sub-humid conditions, being a potential source of biodiesel. The challenge is to understand the physiology of J. curcas, which enables it to live under saline and drought conditions. The seeds of J. curcas used came from Ciego de Ávila Province, Cuba. Seven-day-old seedlings were cultivated in 1.5 L pots with half strength Hoagland solution for 42 days under semi-controlled conditions. NaCl added to solutions in pots provided 75 or 150 mM treatments for 240 h before measurements. Leaf growth, net photosynthesis and stomatal pore area were affected by 150 mM NaCl. Non-photochemical quenching of leaves was only changed by 150 mM NaCl after 24 h; the electron transport rate had a tendency to decrease in leaves under saline conditions. The gene expression pattern changed for SOS1 and HKT1 according to the NaCl used in the medium, indicating active mechanism to deal with Na+ in the cell. In general, Cuban J. curcas plants were able to grow and perform photosynthesis under 75 mM NaCl, which represents 7 dS m-1, a condition that restricts growth for many plant species.
Keywords:
Physic nuts; Salt stress; Gas exchange; SOS1; HKT1
