Figure 8
Model summarizing the cross-talk of copper and ROS homeostasis during drought in N22 flag leaf. In brief, during drought there is lowering of internal copper levels in the flag leaves of tolerant cultivar probably due to differential regulation of copper transporters. This leads to up-regulation of OsSPL9 and consequently of the CSDR-miRNAs. The CSDR-miRNAs then target several copper containing proteins such as plantacyanin and SODs. The observed stabilization of plastocyanin levels even during low cellular copper may indicate the role the ‘copper economy model’ involving the plantacyanins. On the other hand, down regulation of SODs lead to accumulation of ROS. High ROS levels may be responsible for the observed enhanced stomata closure in the tolerant cultivar.
