Nitrate reductase activity control in pineapple plants subjected to low temperatures in different phases of diurnal cycle

• Grant number: 10/04270-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2010
• End date: March 31, 2012
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Helenice Mercier
• Grantee: Aline Tiemi Matsumura
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Previous work at the Laboratory of Plant Physiology IB-USP showed that pineapple plants grown in thermoperiod 28°C light / dark 15°C showed preferential nitrate reductase activity (NR) occurring during dark phase on roots, while control plants, grown in constant temperature of 28°C, showed preferential activity in light phase on leaves. This project will aim to understand the effect of exposuring pineapple plants at low temperatures on the enzymatic activity, trying to discover if there is inter-relationship between the stimulus from lower temperature and phase of the diurnal cycle. Therefore, plants of Ananas comosus L. Merr will be exposed to temperatures of 4 or 10°C for periods of 1, 3, 6 or 12 hours, both in the presence and absence of light. NR activity will be determined by in vivo tests. To check the influence of the phase of the diurnal cycle, in which plants are subjected to cold, 4 stages will be selected in both light and darkness. NR activity will be measured after the removal of plants from the cold condition and after 24 hours of rewarming to 25°C at intervals of three hours. The controls will be maintained at 25°C in all experiments, under the same conditions of each treatment. Once determined the phase of greater induction of NR in leaves and roots, additional tests will be conducted with the purpose of considering the participation in the event of different types of NR: cytoplasmatic and of plasma membrane. This work will try to clarify the differences between leaves and roots responses to cold, depending on the phase of the diurnal cycle and the presence or absence of light, and what form of NR would be the main involved in these responses triggered by lowering the temperature.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

MATSUMURA, Aline Tiemi. Nitrate reductase activity control in pineapple plants subject to low temperatures in different phases of diurnal cycle. 2013. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) São Paulo.