Cell wall structures leading to cultivar differences in softening rates develop early during apple (Malus x domestica) fruit growth

BMC Plant Biology

Research Article

Laurence D Melton¹  Bronwen G Smith¹  Jovyn KT Ng²  Jason W Johnston³  Paul W Sutherland⁴  Ian C Hallett⁴  Roneel Prakash⁴  Miriam I Hall⁴  Roswitha Schröder⁴ 

[1] Food Science, School of Chemical Sciences, The University of Auckland, Private Bag, 92019, Auckland, New Zealand;Food Science, School of Chemical Sciences, The University of Auckland, Private Bag, 92019, Auckland, New Zealand;The New Zealand Institute for Plant & Food Research Limited, Mount Albert Research Centre, Private Bag 92169, 1142, Auckland, New Zealand;The New Zealand Institute for Plant & Food Research Limited, Food Industry Science Centre, Private Bag 11600, 4442, Palmerston North, New Zealand;The New Zealand Institute for Plant & Food Research Limited, Hawkes Bay Research Centre, 4130, Havelock North, New Zealand;The New Zealand Institute for Plant & Food Research Limited, Mount Albert Research Centre, Private Bag 92169, 1142, Auckland, New Zealand;

关键词: Apple;    Cell adhesion;    Cell wall;    Fruit firmness;    Immunofluorescence labelling;    Microstructure;    Pectin;   

DOI  :  10.1186/1471-2229-13-183

 received in 2013-07-22, accepted in 2013-11-12,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundThere is a paucity of information regarding development of fruit tissue microstructure and changes in the cell walls during fruit growth, and how these developmental processes differ between cultivars with contrasting softening behaviour. In this study we compare two apple cultivars that show different softening rates during fruit development and ripening. We investigate whether these different softening behaviours manifest themselves late during ethylene-induced softening in the ripening phase, or early during fruit expansion and maturation.Results‘Scifresh’ (slow softening) and ‘Royal Gala’ (rapid softening) apples show differences in cortical microstructure and cell adhesion as early as the cell expansion phase. ‘Scifresh’ apples showed reduced loss of firmness and greater dry matter accumulation compared with ‘Royal Gala’ during early fruit development, suggesting differences in resource allocation that influence tissue structural properties. Tricellular junctions in ‘Scifresh’ were rich in highly-esterified pectin, contributing to stronger cell adhesion and an increased resistance to the development of large airspaces during cell expansion. Consequently, mature fruit of ‘Scifresh’ showed larger, more angular shaped cells than ‘Royal Gala’, with less airspaces and denser tissue. Stronger cell adhesion in ripe ‘Scifresh’ resulted in tissue fracture by cell rupture rather than by cell-to-cell-separation as seen in ‘Royal Gala’. CDTA-soluble pectin differed in both cultivars during development, implicating its involvement in cell adhesion. Low pectin methylesterase activity during early stages of fruit development coupled with the lack of immuno-detectable PG was associated with increased cell adhesion in ‘Scifresh’.ConclusionsOur results indicate that cell wall structures leading to differences in softening rates of apple fruit develop early during fruit growth and well before the induction of the ripening process.

【 授权许可】

CC BY   
© Ng et al.; licensee BioMed Central Ltd. 2013