HvPap-1 C1A Protease and HvCPI-2 Cystatin Contribute to Barley Grain Filling and Germination

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.

Modulation of autophagy and protease activities by small bioactive compounds to reduce cell death and improve stress-induced microspore embryogenesis initiation in rapeseed and barley

“…These enzymes play a role in plant senescence, programmed cell death (PCD), and proteolysis mediated by abiotic stress, among other processes. 13,14 In animals, cathepsins are well-known lysosomal proteases with a role in autophagy and cell death, 15 in which they have a critical role in the degradation of proteins within autolysosomes, after autophagosome fusion. [16][17][18] However, the role of plant cathepsins in autophagy is still unresolved.…”

Capillary Electrophoresis Mass Spectrometry as A Tool for Untargeted Metabolomics

“…Visualization of aligned datasets to inspect the quality of feature assignment is very practical. Such option together with the possibility for manual peak re-integration is available in MassHunterProfinder software (Agilent Technologies) [113].…”

Programmed Cell Death in Seeds: An Adaptive Mechanism Required for Life

“…PLCPs in plants are divided Programmed Cell Death in Seeds: An Adaptive Mechanism Required for Life DOI: http://dx.doi.org /10.5772/intechopen.86833 into nine subfamilies. Thus, 32, 41, and 45 PLCPs' members have been identified in Arabidopsis, barley, and rice, respectively [49]. PLCPs have no structural relationship to the caspases, and its natural competitive and reversible inhibitors are the phytocystatins which are evolutionarily well conserved [50].…”

“…During barley seed germination, PLCPs were secreted from the scutellar and the aleurone layers to the endosperm to degrade the endosperm Sps [58]. Recently, the results of overexpression and silencing of HvPap-1, a gibberellin (GAs)-induced PLCP gen, indicated that PLCPs are important factors in mobilizing SPs to promote seed germination, and their expression and/or activity are regulated by GAs, ABA, and cystatins [49]. Ricinosomes and nuclear DNA are fragmented during PCD.…”