SUMO wrestling - understanding the molecular basis of drought tolerance in sugarcane : final report 2017/401

Abstract

We report here that neither the plant growth hormone gibberellin (GA) signalling, nor SUMOylation post-translational mechanism, a well-known phenomenon triggered by several abiotic stresses, are involved in water stress-induced growth inhibition of sugarcane leaves. The Q208A commercial sugarcane variety was subjected to water stress condition and conducted targeted experiments to understand the molecular aspects of leaf growth regulation under water deficit. Plants were water stressed gradually by withdrawing irrigation. Growth-related parameters, but not photosynthesis, were significantly affected by water deficit. By day 25 following stress imposition, the youngest leaves ceased growing. Analysis of cell division and elongation regions of youngest developing leaves revealed that neither DELLA protein, a negative regulator of GA, nor conjugation of SUMO1 protein increased in response to water stress, suggesting a complex molecular regulation of stress-induced leaf growth inhibition in sugarcane. Analysis of sugar and energy sensing and signalling genes indicate a possible molecular reprogramming occurring in the basal region of developing leaves during water deficit. Understanding the nature of this molecular reprogramming may lead to important insights on sugarcane leaf growth regulation under water stressed and non-stressed conditions.