Adriana Grandis1, Débora C C Leite1, Eveline Q P Tavares1, Bruna C Arenque-Musa1, Jonas W Gaiarsa2, Marina C M Martins1, Amanda P De Souza1,3, Leonardo D Gomez4, Claudia Fabbri5, Benedetta Mattei5,6, Marcos S Buckeridge1. 1. Laboratory of Plant Physiological Ecology (LAFIECO), Department of Botany, Institute of Biosciences, University of São Paulo, São Paulo, SP, Brazil. 2. GaTE Lab, Department of Botany, Institute of Bioscience, University of São Paulo, São Paulo, Brazil. 3. Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA. 4. Centre for Novel Agricultural Products, Department of Biology, University of York, UK. 5. Department of Biology and Biotechnology 'C. Darwin', University of Rome - Sapienza, Italy. 6. Department of Life, Health and Environmental Sciences, University of L'Aquila, Italy.
Abstract
BACKGROUND AND AIMS: Cell wall disassembly occurs naturally in plants by the action of several glycosyl-hydrolases during different developmental processes such as lysigenous and constitutive aerenchyma formation in sugarcane roots. Wall degradation has been reported in aerenchyma development in different species, but little is known about the action of glycosyl-hydrolases in this process. METHODS: In this work, gene expression, protein levels and enzymatic activity of cell wall hydrolases were assessed. Since aerenchyma formation is constitutive in sugarcane roots, they were assessed in segments corresponding to the first 5 cm from the root tip where aerenchyma develops. KEY RESULTS: Our results indicate that the wall degradation starts with a partial attack on pectins (by acetyl esterases, endopolygalacturonases, β-galactosidases and α-arabinofuranosidases) followed by the action of β-glucan-/callose-hydrolysing enzymes. At the same time, there are modifications in arabinoxylan (by α-arabinofuranosidases), xyloglucan (by XTH), xyloglucan-cellulose interactions (by expansins) and partial hydrolysis of cellulose. Saccharification revealed that access to the cell wall varies among segments, consistent with an increase in recalcitrance and composite formation during aerenchyma development. CONCLUSION: Our findings corroborate the hypothesis that hydrolases are synchronically synthesized, leading to cell wall modifications that are modulated by the fine structure of cell wall polymers during aerenchyma formation in the cortex of sugarcane roots.
BACKGROUND AND AIMS: Cell wall disassembly occurs naturally in plants by the action of several glycosyl-hydrolases during different developmental processes such as lysigenous and constitutive aerenchyma formation in sugarcane roots. Wall degradation has been reported in aerenchyma development in different species, but little is known about the action of glycosyl-hydrolases in this process. METHODS: In this work, gene expression, protein levels and enzymatic activity of cell wall hydrolases were assessed. Since aerenchyma formation is constitutive in sugarcane roots, they were assessed in segments corresponding to the first 5 cm from the root tip where aerenchyma develops. KEY RESULTS: Our results indicate that the wall degradation starts with a partial attack on pectins (by acetyl esterases, endopolygalacturonases, β-galactosidases and α-arabinofuranosidases) followed by the action of β-glucan-/callose-hydrolysing enzymes. At the same time, there are modifications in arabinoxylan (by α-arabinofuranosidases), xyloglucan (by XTH), xyloglucan-cellulose interactions (by expansins) and partial hydrolysis of cellulose. Saccharification revealed that access to the cell wall varies among segments, consistent with an increase in recalcitrance and composite formation during aerenchyma development. CONCLUSION: Our findings corroborate the hypothesis that hydrolases are synchronically synthesized, leading to cell wall modifications that are modulated by the fine structure of cell wall polymers during aerenchyma formation in the cortex of sugarcane roots.
Authors: Eveline Q P Tavares; Amanda P De Souza; Grayce H Romim; Adriana Grandis; Anna Plasencia; Jonas W Gaiarsa; Jacqueline Grima-Pettenati; Nathalia de Setta; Marie-Anne Van Sluys; Marcos S Buckeridge Journal: J Exp Bot Date: 2019-01-07 Impact factor: 6.992