%0 Journal Article
%@ 1435-8603
%A Sivasakthi, K
%A Tharanya, M
%A Zaman‐Allah, M
%A Kholová, J
%A Thirunalasundari, T
%A Vadez, V
%D 2020
%F icrisat:11620
%I Wiley
%J Plant Biology (TSI)
%K Apoplastic pathway, Aquaporins, Cell-to-cell  pathway, Drought, Hydraulics, Roots, Water saving
%P 769-780
%T Transpiration difference under high evaporative demand in chickpea ( Cicer arietinum L.) may be explained by differences in the water transport pathway in the root cylinder
%U http://oar.icrisat.org/11620/
%X Terminal drought substantially reduces chickpea yield. Reducing water use at vegetative  stage by reducing transpiration under high vapor pressure deficit (VPD), i.e. under dry/  hot conditions, contributes to drought adaptation. We hypothesized that this trait could  relate to differences in a genotype’s dependence on root water transport pathways and  hydraulics.  • Transpiration rate responses in conservative and profligate chickpea genotypes were  evaluated under increasing VPD in the presence/absence of apoplastic and cell-to-cell  transport inhibitors.  • Conservative genotypes ICC 4958 and ICC 8058 restricted transpiration under high  VPD compared to the profligate genotypes ICC 14799 and ICC 867. Profligate genotypes  were more affected by aquaporin inhibition of the cell-to-cell pathway than conservative  genotypes, as measured by the root hydraulic conductance and transpiration  under high VPD. Aquaporin inhibitor treatment also led to a larger reduction in root  hydraulic conductivity in profligate than in conservative genotypes. In contrast, blockage  of the apoplastic pathway in roots decreased transpiration more in conservative  than in profligate genotypes. Interestingly, conservative genotypes had high early vigour,  whereas profligate genotypes had low early vigour.  • In conclusion, profligate genotypes depend more on the cell-to-cell pathway, which  might explain their higher root hydraulic conductivity, whereas water-saving by  restricting transpiration led to higher dependence on the apoplastic pathway. This  opens the possibility to screen for conservative or profligate chickpea phenotypes using  inhibitors, itself opening to the search of the genetic basis of these differences.
%Z The authors acknowledge support from ICRISAT for a Blue  Sky Research Project on ‘Developing crops with high productivity at high temperatures’, and the CGIAR Research Program (CRP) on Grain Legumes. The writing of this paper was supported by the Make Our Planet Great Again (MOPGA)  ICARUS project (Improve Crops in Arid Regions and Future  Climates) funded by the Agence Nationale de la Recherche  (ANR, grant ANR-17-MPGA-0011). Special thanks to Mrs.  Rekha Baddam and Mr. Mathew V. Joseph for help with statistical analysis and growth chamber operations.