CELLULASE6 and MANNANASE7 Affect Cell Differentiation and Silique Dehiscence

Abstract

Cellulases, hemicellulases, and pectinases play important roles in fruit development and maturation. Although mutants with defects in these processes have not been reported for cellulase or hemicellulase genes, the pectinases ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE1 (ADPG1) and ADPG2 were previously shown to be essential for silique dehiscence in Arabidopsis (). Here, we demonstrate that the cellulase gene () and the hemicellulase gene () function in the development and dehiscence of Arabidopsis siliques. We found that these genes were expressed in both vegetative and reproductive organs and that their expression in the silique partially depended on the INDEHISCENT and ALCATRAZ transcription factors. Cell differentiation was delayed in the dehiscence zone of and mutant siliques at early flower development stage 17, and a comparison of the spatio-temporal patterns of and expression with the locations of delayed cell differentiation in the and mutants revealed that CEL6 and MAN7 likely indirectly affect the timing of cell differentiation in the silique valve at this stage. CEL6 and MAN7 were also found to promote cell degeneration in the separation layer in nearly mature siliques, as cells in this layer remained intact in the and mutants and the double mutant, whereas they degenerated in the wild-type control. Phenotypic studies of single, double, triple, and quadruple mutants revealed that higher-order mutant combinations of, , and and produced more severe silique indehiscent phenotypes than the corresponding lower-order mutant combinations, except for some combinations involving, , and Our results demonstrate that the ability of the silique to dehisce can be manipulated to different degrees by altering the activities of various cell wall-modifying enzymes.

Comprehensive analysis of polygalacturonase family highlights candidate genes related to pollen development and male fertility in wheat (Triticum aestivum L.)

“…TaPG87 and TaPG95 were found to share high homology with ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE2 (ADPG2). Our qRT-PCR results also demonstrated that both genes are expressed in the late stage (trinucleate) in the fertile anthers in the same manner as many of the pollen-specific PGs mentioned above, and thus we suggest that they are involved in the separation of pollen grains and the cracking of anthers, which are the roles of ADPG1 and ADPG2 in Arabidopsis [61]. The downregulated expression of TaPG87 in the fertile anthers was not expected, but this result was verified by RT-PCR (Additional file 9: Figure S4) and qRT-PCR.…”

New roles of NO TRANSMITTING TRACT and SEEDSTICK during medial domain development in Arabidopsis fruits

“…The subtle reduction in fertility observed is probably due to the involvement of other redundant proteins or additional enzymes. This was recently shown for silique dehiscence zone formation, where various cell wall-modifying enzymes participate, such as ARABIDOPSIS DEHISCENCE ZONE POLYGARACTURONASE 1 (ADPG1), ADPG2, CELLULASE 6 (CEL6) and MANNANASE 7 (MAN7) (Ogawa et al, 2009;He et al, 2018). On the other hand, the altered wax deposition in septum cells is a sign of altered lipid metabolism or transport.…”

Mechanism and Regulation of Silique Dehiscence, Which Affects Oil Seed Production

“…Those genes were expressed in both vegetative and reproductive organs, and their expressions in the silique was partially regulated by the INDEHISCENT and ALCATRAZ transcription factors. They indirectly affect the time of cell differentiation in valves and promote the degradation of the separation layer cells to facilitate silique dehiscence (He et al, 2018). Xyloglucan endotransglycosylase (XET) is another enzyme involved in cell wall loosening (Fry et al, 1992).…”