HvPap-1 C1A Protease and HvCPI-2 Cystatin Contribute to Barley Grain Filling and Germination. Issue 4 (24th February 2016)

• Record Type: Journal Article
• Authors: Diaz-Mendoza, Mercedes; Dominguez-Figueroa, Jose D.; Velasco-Arroyo, Blanca; Cambra, Ines; Gonzalez-Melendi, Pablo; Lopez-Gonzalvez, Angeles; Garcia, Antonia; Hensel, Goetz; Kumlehn, Jochen; Diaz, Isabel; Martinez, Manuel
• Is Part Of: Plant physiology. Volume 170:Issue 4(2016)
• Page Start: 2511
• Page End: 2524
• Publication Date: 2016-02-24
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.15.01944
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : Over-expressing or silencing proteases or their inhibitors alter the metabolite composition of the grain and modify the germination process in barley Abstract: Proteolysis is an essential process throughout the mobilization of storage proteins in barley ( Hordeum vulgare ) grains during germination. It involves numerous types of enzymes, with C1A Cys proteases the most abundant key players. Manipulation of the proteolytic machinery is a potential way to enhance grain yield and quality, and it could influence the mobilization of storage compounds along germination. Transgenic barley plants silencing or over-expressing the cathepsin F-like HvPap-1 Cys protease show differential accumulation of storage molecules such as starch, proteins, and free amino acids in the grain. It is particularly striking that the HvPap-1 artificial microRNA lines phenotype show a drastic delay in the grain germination process. Alterations to the proteolytic activities in the over-expressing and knock-down grains associated with changes in the level of expression of several C1A peptidases were also detected. Similarly, down-regulating cystatin Icy-2, one of the proteinaceous inhibitors of the cathepsin F-like protease, also has important effects on grain filling. However, the ultimate physiological influence of manipulating a peptidase or an inhibitor cannot be always predicted, since the plant tries to compensate the modified proteolytic effects by modulating the expression of some other peptidases or their inhibitors.