HKU scientists help soybeans to grow in saline soil
Scientists at University of Hong Kong have studied the molecular mechanisms controlling salt-induced adaptive changes in soybeans.
Plants acclimate to salt stress by modifying their root architecture, generating ion pumps and producing specific metabolites. The process relies heavily on signalling molecules: in particular two lipid classes, phosphatidic acid and oxylipins.
Previous research has shown that phosphatidic acid signals can be formed with a protein named ACBP. ACBPs can be found in a lot of eukaryotes and binds acyl-CoA esters, the activated form of fatty acids in lipid metabolism.
By examining soybean roots in salt solution, the team noticed variants of the protein - ACBP3 and ACBP4, were smaller than the native forms that emerged during the first few hours of treatment. When the two protein variants are overexpressed, soybeans can detect and adapt to saline soil better.
“These proteins were truncated because their pre-mRNAs were cut and rejoined in an atypical way, commonly known as alternative splicing. This phenomenon was never seen before in plant ACBPs,” commented the programme lead Professor Chye Mee Len (Croucher Senior Research Fellowship 2007).
The team also unveiled the mechanistic role of these proteins in regulating the production of oxylipin signals. When exposed to salt stress, the enzymes that are essential to the production of this signal become more active. The team is now exploring genetic engineering as a solution to improve salt tolerance in soybean and other plant crops, hoping to promote crop yield in view of climate change. The findings are published in The Plant Cell.