科研之友
微信
新浪微博
Facebook
分享链接
摘要
In the present study, expression patterns of two different wheat cystatins (WCs) were studied under the influence of jasmonate signaling in triggering resistance against Karnal bunt (KB). Cystatins are cysteine proteinase inhibitors (CPI) constituting a multigene family which regulate the activity of endo- and/or exogenous cysteine proteinases (CP). Two wheat varieties HD-29 (resistant, R) and WH-542 (susceptible, S) were pre-conditioned with jasmonate and then artificially inoculated with sporidial suspension of Tilletia indica to study its influence in inducing defense by regulating cystatin genes. On the transcriptional level, WC4 and WC5 gave different temporal expression patterns. Expression of WC4 was higher in boot emergence stage which is most susceptible to KB and then slowly declined in both varieties. Expression of WC5 showed an entirely reverse pattern of expression, which kept on rising as the grains matured. Cystatin activity determination by inhibitor assay gave higher activity in resistant variety and under JA treatment. Estimation of specific activity of total cystatin at different days after inoculation (DAI) showed that JA positively induced cystatin expression in both varieties but R variety always registered a greater cystatin expression than the susceptible one (P<0.05). In plants inoculated with pathogen, initially there was a rise in cystatin activity which gradually decreased 7 DAI when compared with the un-inoculated plants. Based on these findings it is clearly demonstrated that jasmonate acts as a potential activator of induced resistance by up-regulating cystatin expression and provides the conditioning effect prior to infection through the maintenance of critical balance of CP/CPI interaction. However, different cystatin genes show different temporal expression patterns and may play different roles at various developmental stages of the grain.
- 出版日期2012-9-10
