A Comparative Study of Proteolytic Mechanisms during Leaf Senescence of Four Genotypes of Winter Oilseed Rape Highlighted Relevant Physiological and Molecular Traits for NRE Improvement

Plants

Alexandra Girondé²  Marine Poret²  Philippe Etienne²  Jacques Trouverie²  Alain Bouchereau¹  Françoise Le Cahérec¹  Laurent Leport¹  Marie-Françoise Niogret¹  Jean-Christophe Avice² 

[1] INRA, UMR 1349 Institut de Génétique, Environnement et Protection des Plantes, Agrocampus Ouest, Université de Rennes 1, F-35653 Le Rheu, France;UMR INRA-UCBN 950 Ecophysiologie Végétale, Agronomie & Nutritions N.C.S., Université de Caen Normandie, F-14032 Caen, France;

关键词: Brassica napus;    N remobilization;    genotypic variability;    proteolysis;    acidic proteases;   

DOI  :  10.3390/plants5010001

来源: mdpi

【 摘 要 】

Winter oilseed rape is characterized by a low N use efficiency related to a weak leaf N remobilization efficiency (NRE) at vegetative stages. By investigating the natural genotypic variability of leaf NRE, our goal was to characterize the relevant physiological traits and the main protease classes associated with an efficient proteolysis and high leaf NRE in response to ample or restricted nitrate supply. The degradation rate of soluble proteins and D1 protein (a thylakoid-bound protein) were correlated to N remobilization, except for the genotype Samouraï which showed a low NRE despite high levels of proteolysis. Under restricted nitrate conditions, high levels of soluble protein degradation were associated with serine, cysteine and aspartic proteases at acidic pH. Low leaf NRE was related to a weak proteolysis of both soluble and thylakoid-bound proteins. The results obtained on the genotype Samouraï suggest that the timing between the onset of proteolysis and abscission could be a determinant. The specific involvement of acidic proteases suggests that autophagy and/or senescence-associated vacuoles are implicated in N remobilization under low N conditions. The data revealed that the rate of D1 degradation could be a relevant indicator of leaf NRE and might be used as a tool for plant breeding.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.