|Support type:||Scholarships in Brazil - Scientific Initiation|
|Effective date (Start):||January 01, 2020|
|Effective date (End):||December 31, 2020|
|Field of knowledge:||Agronomical Sciences - Agronomy - Soil Science|
|Principal Investigator:||André Rodrigues dos Reis|
|Grantee:||Nandhara Angélica Carvalho Mendes|
|Home Institution:||Faculdade de Ciências e Engenharia. Universidade Estadual Paulista (UNESP). Campus de Tupã. Tupã , SP, Brazil|
Water stress is one of the major limiting factor for plant survival, which can be minimized by nickel (Ni) supply due to its proven role in cell defense against oxidative damage caused by reactive oxygen species. In addition, Ni is essential for nitrogen (N) metabolism, working as a key element for N fixation and assimilation processes in leguminous plants. Much of what is known about Ni role has been reported in soybean, existing a limited data about others leguminous species. The hypothesis to be tested is that the Ni supply can improve N physiological use and reduce drought stress in cowpea genotypes. Therefore, the objectives of this study are: (I) to evaluate the Ni effect on N metabolism and antioxidant system and (II) to assess the Ni effect on leaf ultrastructure, nutrients, carbohydrates, water use, gas exchange and cowpea grain yield in response to drought. For this purpose, a greenhouse experiment will be installed containing cowpea plants grown in fertilized soils with five doses of Ni (0, 0.25, 0.5, 1 and 2 mg kg-1 Ni) under different available water capacities (AWC): 30% (water stress) and 80% (control). For physiological (photosynthetic activity, chlorophyll A fluorescence, leaf matrix potential), biochemical (antioxidant, urease, proline, ureids) and nutritional analyzes, leaves and nodules will be collected during the R1 stage. The plants will be grown until the end of the cycle to determine the production components and grain yield. Differential metabolic responses to Ni supply may highlight information that will contribute to culture resilience in the face of global climate change.