RESUMO
MADS-domain transcription factors play pivotal roles in numerous developmental processes in Arabidopsis thaliana. While their involvement in flowering transition and floral development has been extensively examined, their functions in root development remain relatively unexplored. Here, we explored the function and genetic interaction of three MADS-box genes (XAL2, SOC1 and AGL24) in primary root development. By analyzing loss-of-function and overexpression lines, we found that SOC1 and AGL24, both critical components in flowering transition, redundantly act as repressors of primary root growth as the loss of function of either SOC1 or AGL24 partially recovers the primary root growth, meristem cell number, cell production rate, and the length of fully elongated cells of the short-root mutant xal2-2. Furthermore, we observed that the simultaneous overexpression of AGL24 and SOC1 leads to short-root phenotypes, affecting meristem cell number and fully elongated cell size, whereas SOC1 overexpression is sufficient to affect columella stem cell differentiation. Additionally, qPCR analyses revealed that these genes exhibit distinct modes of transcriptional regulation in roots compared to what has been previously reported for aerial tissues. We identified 100 differentially expressed genes in xal2-2 roots by RNA-seq. Moreover, our findings revealed that the expression of certain genes involved in cell differentiation, as well as stress responses, which are either upregulated or downregulated in the xal2-2 mutant, reverted to WT levels in the absence of SOC1 or AGL24.
RESUMO
Barley malting depends on hydrolytic enzymes that degrade storage macromolecules. Identifying barley cultivars with proteolytic activity that guarantees appropriate foaming, flavor, and aroma in the beer is of great importance. In this work, the proteolytic activity and profiles of brewing malt from Mexican barley cultivars were analyzed. Data showed that Cys- (at 50°C) and Ser-proteases (at 70°C) are the major contributors to proteolytic activity during mashing. Essential amino acids, necessary for fermentation and production of good flavor and aroma in beer, were detected at the end of mashing. According to our results, Mexican cultivar HV2005-19 exhibits similar proteolytic activities as those from cultivar Metcalfe, which is one of the most utilized for the brewing industry. Moreover, we propose Cys- and Ser-proteases as biochemical markers during mashing at 50 and 70°C, respectively, to select barley cultivars for beer production. PRACTICAL APPLICATIONS: Proteolytic activity, which depends on activation and de novo synthesis of proteases in the aleurone layer of barley seeds, is crucial in beer production. Identifying new barley varieties that have optimal proteolytic activities is of great interest for genetic improvement programs. In this study, we propose the variety HV2005-19 as a genotype with Cys- and Ser-proteases activity similar to that from Metcalfe, which is a top variety in the brewing industry.