Washington: A Purdue University study has discovered genetic evidence of how some plants adapt to live in unfavourable conditions.
The findings could one day be used to help food crops survive in new or changing environments.
David Salt noticed several years ago that a variant of the research plant Arabidopsis thaliana that could tolerate higher levels of sodium had come from coastal areas.
To test the observation, Salt grew more than 300 Arabidopsis thaliana plants from seeds gathered across Europe. The plants were grown in non-saline soil and their leaf-sodium content was measured.
Each plant``s origination was mapped, and those with the highest sodium contents were found to have come from seeds collected close to a coast or area with high saline soil.
All plants were analyzed using genome-wide association mapping, which compares the genomes of a number of plants with a shared physical trait to identify genes that may account for variation in this characteristic.
Salt found that the plants that accumulate the highest sodium levels in their leaves had a weak form of the gene HTK1, which regulates sodium intake distribution to leaves.
It has long been known that plants are adapted to their local soil environments, but the molecular basis of such adaptation has remained elusive.
Salt said this is some of the first evidence linking genetic changes with adaptation to specific environmental factors.
The findings were published in the journal PLoS Genetics.