Banca de DEFESA: CASTRO ALVES DA SILVA JUNIOR

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : CASTRO ALVES DA SILVA JUNIOR
DATE: 29/07/2025
TIME: 10:00
LOCAL: Sala 24 - Departamento de Solos
TITLE:

Combined use of silicon and plant growth-promoting bacteria in mitigating water stress in upland rice

KEY WORDS:

Water stress, Bacillus aryabhattai, Stress mitigation in plants.

PAGES: 68
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Fertilidade do Solo e Adubação
SUMMARY:

Upland rice has great potential for domestic grain supply in Brazil, as its expansion could end monoculture and provide a solution to the high food prices, benefiting low-income populations. However, its production is frequently threatened by water stress caused by prolonged drought periods, a consequence of climate crises bringing high temperatures to tropical regions, which have already become a reality, causing concern among producers when choosing rice for cultivation. In this context, the integration of strategies to mitigate the impacts of drought is essential, even though they are already known, such as the use of silicon (Si) and plant growth-promoting bacteria (PGPB), which have shown significant potential in alleviating plant stress. Therefore, this study aims to test the efficiency of combining Si and PGPB in mitigating water stress in upland rice, through physiological, biochemical, and molecular analyses of rice plants subjected to stress. This research is being conducted in greenhouse 01-A at EMBRAPA – Agrobiology, with the goal of investigating the potential of combining silicon and plant growth-promoting bacteria to mitigate water stress. The Mira rice variety will be used under controlled water stress conditions. The experimental design will follow a triple factorial scheme (2 x 2 x 3), involving water conditions (moderate stress and ideal), silicon fertilization (with and without Si), and PGPB inoculation methods (single, re-inoculation, and no inoculation), totaling 96 experimental plots. The plants will be evaluated for biochemical, physiological, molecular, and productive responses at two stages: 14 days after floral differentiation and at the end of the cycle. The Si source chosen was Sifol Powder® fertilizer, while the PGPB used, known for its ability to form endospores and tolerate extreme conditions, was Bacillus aryabhattai CMAA 1363, via the commercial product AURAS®. Water stress will be induced by reducing the soil's field capacity to 40%, simulating adverse conditions, while control pots will be maintained at 70%. The results show variations in the effects of the treatments under the variables studied, but inoculation with the bacteria, reinoculation, and application of Si increased the relative expression of genes that encode proteins that can promote efficient water use. These factors also favored the enzymatic and non-enzymatic antioxidant activity of the plants by stabilizing and, in some cases, increasing the activity of SOD, CAT, and the AsA/DHA ratio in both leaves and roots.

COMMITTEE MEMBERS:
Interno - 1399485 - ANDRES CALDERIN GARCIA
Presidente - ***.180.573-** - MANLIO SILVESTRE FERNANDES - UFRRJ
Externa à Instituição - MARCIA SOARES VIDAL - EMBRAPA