A new soy source for crop salt tolerance

A collaborative research project between Chinese and Australian scientists has shown how soybean can be bred to better tolerate soil salinity.  The findings are published as a featured article in The Plant Journal in December, 2014. The co-first authors are Associate Prof Rongxia Guan, Mr. Yue Qu and Associate Prof Yong Guo, and the corresponding authors are Prof. Lijuan Qiu and Assoc. Prof Matthew Gilliham.

The salt-affected agriculture land is rapidly increasing and predicted to double by 2050. Many commercial crops are sensitive to soil salinity and this can cause major losses to crop yields. An increase in the salt tolerance of crops will be effective for improving crop productivity and food security in the condition that on option for expanding the area of agricultural land.

It was reported that the salt tolerance in soybean is controlled by a single dominant allele Ncl nearly half century ago. A major QTL related to soybean salt tolerance was mapped and validated on chromosome 3 by different research groups, but no information of positional cloning of this important locus was found.

After examining the genetic sequence of several hundred soybeans, research led by Prof. Lijuan Qiu at the Institute of Crop Sciences, Chinese Academy of Agricultural Sciences in Beijing pinpointed a candidate salt tolerance gene, which spent more than 10 years.  Then collaborating with Assoc. Prof. Matthew Gilliham’s team at the ARC Centre of Excellence in Plant Energy Biology, University of Adelaide, further characterized the function of this gene.

“We initially identified the gene by comparing two commercial cultivars so we were both surprised and pleased to see that this gene also conferred salt tolerance in some other commercial cultivars, old domesticated soybeans and even wild soybeans; it appears that this gene was lost when breeding new cultivars of soybean in areas without salinity, this has left many new cultivars susceptible to the rapid increases we are currently seeing in soil salinity around the world”, said Prof. Qiu.

By identifying the gene, genetic markers can now be used in breeding programs to ensure that salt tolerance can be maintained in future cultivars of soybean that will be grown in areas prone to soil salinity.

Talking about the future prospects of this research Assoc. Prof. Gilliham added, “This gene functions in a completely new way from other salt tolerance genes we know about. Efforts are still ongoing to discover mechanism underlying  GmSALT3 protein. We are excited about using this information to find similar genes in different crops such as wheat and grapevine, to selectively breed for their enhanced salt tolerance”.

The article is highlighted on The Plant Journal's home page and available for free download for one month from the day of online publication.