Bioregulatory Role of “thiourea” in Multistress Tolerance of the Indian Mustard (brassica Juncea)

Thiourea (TU) application has been identified as a novel bioregulator technology, for imparting stress tolerance in crop plants. TU application has shown normal growth of Brassica juncea seedlings under salinity stress. In order to study the molecular mechanism underlying TU mediated response, genome wide transcriptome profiling of Brassica juncea seeds was undertaken. In one hour soaking time, the expression level of 111 genes was altered in response to NaCl treatment. Of these, 33 genes were regulated towards the level of distilled water control if thiourea was added along with NaCl treatment. These genes were classified as ‘Thiourea responsive genes’ including particularly those associated with calcium signaling, oxidative stress and hormonal regulation. The effectiveness of thiourea under the combined effect of salt, drought and cold stress was also established, by validating the expression level of important thiourea responsive genes through real-time PCR. Thiourea mediated modulation in the gene expression varied and depended upon the magnitude of stress present in the system. The time kinetics studies showed that one hour incubation time was sufficient for the maximal effect of thiourea action. In conclusion, the result suggested that thiourea mediated changes in the expression profile of various stress responsive genes, can impart stress tolerance in Brassica juncea. The results imply that, thiourea can be considered as an important bioregulatory molecule, for increasing stress tolerance of crops under field conditions.