Impact of combined sulfur deficiency and water stress on nodulated pea root system architecture, water and nutrient uptake
Abstract
Impact of combined sulphur deficiency and drought stress on pea root system architecture, water and nutrient uptake.
Besides playing an important role in plant growth, photosynthesis and seed yield, sulphur is an essential nutrient for symbiotic nitrogen fixation (SNF) in nodulated legumes like pea. Nitrogenase, the enzyme which reduces atmospheric nitrogen in root nodule bacteria, is rich in sulphur. Moreover, water stress in pea causes abscisic acid induced stomatal closure leading to reduced photosynthesis and growth. As we face increasing drought conditions and sulphur deficiency, the objective of this study is to understand the effect of the combination of these two stresses on pea root architecture, water and nutrient uptake, either by the roots of by the nodules (via SNF). A structure-function approach is followed to understand the water and nutrient acquisition using three genotypes Kayanne, Cameor and Cameor2684 which contains a nonsense mutation in the gene encoding the vacoular sulphate transporter SULTR4. Pea plants were grown for high throughput phenotyping and exposure to stress conditions in the RhizoTubes® of the Plant Phenotyping Platform for Plant and Microorganism Interaction (4PMI platform) and exposed to sulphur deficiency, water stress and a combination of both stresses. At the end of the three-weeks stress period, the pea plants were harvested for measurement of morphological and ecophysiological parameters as well as multi-elemental analysis (using Inductively Coupled Plasma Mass Spectrometry (ICP-MS)) of different tissues. Moreover, non-destructive images of root architecture were obtained from the image acquisition system associated to RhizoTubes®. Combined root image analysis and ecophysiological analyses of the obtained results will will be carried out to uncover the impact of drought stress and sulfur deficiency as well as the interaction between these two stresses on root architecture and function.