Thiourea, a ROS scavenger, regulates source-to-sink relationship to enhance crop yield and oil content in Brassica juncea (L.).
In the present agricultural scenario, the major thrust is to increase crop productivity so as to ensure sustainability. In an earlier study, foliar application of thiourea (TU; a non physiological thiol based ROS scavenger) has been demonstrated to enhance the stress tolerance and yield of different crops under field condition. Towards this endeavor, present work deals with the effect of TU on photosynthetic efficiency and source-to-sink relationship of Indian mustard (Brassica juncea) for understanding its mode of action. The application of TU increased the efficiency of both PSI and PSII photosystems and vegetative growth of plant. The comparative analysis of sucrose to starch ratio and expression level of sugar transporters confirmed the higher source and sink strength in response to TU treatment. The biochemical evidence in support of this was derived from higher activities of sucrose phosphate synthase and fructose-1,6-bis-phosphatase at source; and sucrose synthase and different classes of invertases at both source and sink. This indicated an overall increase in photoassimilate level at sink. An additional contribution through pod photosynthesis was confirmed through the analysis of phosphoenol pyruvate carboxylase enzyme activity and level of organic acids. The increased photoassimilate level was also co-ordinated with acetyl coA carboxylase mediated oil biosynthesis. All these changes were ultimately reflected in the form of 10 and 20% increase in total yield and oil content, respectively under TU treatment as compared to control. Additionally, no change was observed in oil composition of seeds derived from TU treated plants. The study thus signifies the co-ordinated regulation of key steps of photosynthesis and source-to-sink relationship through the external application of TU resulting in increased crop yield and oil content.
Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India.
Manish
M
Pandey
Ashish Kumar
AK
Srivastava
Stanislaus Francis
SF
D'Souza
Suprasanna
S
Penna
D000103:Acetyl-CoA Carboxylase / Q000235:genetics / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006597:Fructose-Bisphosphatase / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D009149:Mustard Plant / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D010730:Phosphoenolpyruvate Carboxylase / Q000235:genetics / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects*; D018515:Plant Leaves / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D010938:Plant Oils / Q000378:metabolism; D012639:Seeds / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D013213:Starch / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism; D013890:Thiourea / Q000494:pharmacology*; D043324:beta-Fructofuranosidase / Q000235:genetics / Q000378:metabolism
D016166:Free Radical Scavengers; D010938:Plant Oils; D013395:Sucrose; D013213:Starch; D005964:Glucosyltransferases; C022699:sucrose synthase; C022698:sucrose-phosphate synthase; D006597:Fructose-Bisphosphatase; D043324:beta-Fructofuranosidase; D010730:Phosphoenolpyruvate Carboxylase; D000103:Acetyl-CoA Carboxylase; D013890:Thiourea