Physiological and molecular responses of Eucalyptus globulus and E. grandis to low temperature stress

Author(s)

Adilson Pereira Domingues Júnior

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2016-03-23

Examining board members

Paulo Mazzafera; Gustavo Habermann; Igor Cesarino; Ladaslav Sodek; Rafael Vasconcelos Ribeiro

• Advisor: Paulo Mazzafera

Abstract

Perennial plants need to survive periodic changes in their environment and must provide mechanisms that allow them to survive this unstable condition, through anatomical, cellular and molecular changes. Stresses by low temperatures represent one of the main elements limiting geographic distribution and seasonal growth of various plants, affecting quality and productivity in crops and forest plantations. Cold stress promotes reduction in photosynthetic rate and stimulates the biosynthesis of defensive compounds such as lignin. Although this compound has important biological role, the presence of lignin appears as a limiting factor for pulp production from hardwood trees such as eucalyptus. Eucalyptus is the most important forest culture in Brazil, the world's largest producer of pulp. This industry is responsible for generating more than 150,000 jobs in the country. Several studies focusing on the effect of low temperatures on eucalyptus are found in the literature; however, few of them analyze the impact of this form of stress on energy metabolism of perennial plants, as well as their impact vegetative development. Thus, the main objective of this study was to characterize the impact of low temperatures in physiological, metabolic and molecular parameters of two eucalyptus species, Eucalyptus globulus and E. grandis. The results showed that cold stress affected the plant cell wall deposition in both species, promoting higher development of E. globulus stems. Moreover, the expression of energy balance genes and alterations in primary metaboloma of leaves and stems of E. globulus and E. grandis are reported at the present work. Distinct cold stress responses were observed for both eucalyptus species, particularly regard to energy modulation, carbohydrate metabolism and biomass allocation. In consequence, this work opens new frontiers to be explored in future studies aiming the improvement of productivity of different eucalyptus species grown in Brazil and world (AU)

• FAPESP's process: 11/02575-5 - Physiological and molecular responsesof Eucalyptus globulus and E. grandis to cold stress
• Grantee: Adilson Pereira Domingues Júnior
• Support Opportunities: Scholarships in Brazil - Doctorate