Peanut Gets an Upgrade Against Drought and Salinity

Peanut (Arachis hypogaea L.) is one of the economically important oil and food crops. Peanut is generally grown across a wide range of environments including rain-fed conditions. Because of this, drought is a main limiting factor to peanut production in the semi-arid areas. The development of salinity and drought stress-tolerant peanut to exploit the drought-prone and salinity-affected areas of the world has been imperative these past years. Now, mannitol may just be the thing that would make it a reality.

Mannitol accumulation in most plants works for the alleviation of salinity and osmotic-induced stresses. However, it is not naturally synthesized in peanut. The mtlD gene (from Escherichia coli) codes for an enzyme that converts fructose 2 with 6-phosphate to mannitol1-phosphate. Peanuts transformed with mtlD were evaluated for salinity and drought stress tolerance. The overexpression of the mtlD gene translated to the transgenic peanuts' improved tolerance to salinity and drought. This was revealed by better growth and physiological parameters like mannitol content, total chlorophyll content, and relative water content in transgenic peanuts.

The better performance of the transgenic plants was attributed to the stress-shielding role of mannitol. However, the mtlD expression causing the activation of other protective reactions in transgenic peanut may also be possible.

Read more at: http://www.cropj.com/thankappan_8_3_2014_413_421.pdf.