IND and HEC3 are required for normal expression of ADPG1 in the silique dehiscence zone and seed abscission zone, respectively. Transcriptional regulation of ADPG1, ADPG2 and QRT2 by jasmonic acid, and of ADPG2 by ethylene. Jasmonic acid and ethylene act together with abscisic acid to regulate floral organ abscission, in part by promoting QRT2 expression
PG activity increases during ripening. Ripening specific pectin methylesterase, active in vivo, appears to enhance PG-mediated pectin ultra-degradation, resulting in cell wall dissolution and deciduous fruit trait. Some pectin methylesterase isozymes are apparently inactive in vivo, particularly in green fruit and throughout ripening in the Hard Pick line, limiting PG-mediated pectin depolymerization which results in moderately difficult fruit separation from the calyx
level of PG1 mRNA is stimulated in sepals, petals, and stamens during the flower-opening process. Expression of the gene is high during pistil-development phases, showing a decreasing trend toward flower opening and an increase in senescence. During maturation and ripening, levels of PG1 mRNA are the highest of all those quantified during fruit development. PG1 transcription is strongly activated during seed maturation and drying
a 8 kDa protein (ACT) from the PG1 protein complex is capable of converting the gene product PG2 into a more active and heat-stable form, which increases PG-mediated pectin degradation in vitro and stimulates PG-mediated tissue breakdown in planta. Addition of the 8 kDa protein to tomato PG2 causes a 4fold to 5fold increase in activity
tomato polygalacturonase activity is influenced indirectly by the presence of active tomato pectinmethylesterase and vice versa during thermal and high-pressure treatment
amount of pectin in tomato pomace is high enough to obtain high levels of polygalacturonase. Production of polygalacturonase grown on pectin as a sole carbon source, increases with the time of cultivation
expression of genes pghAxc and pghBxc, encoding functional polygalacturonase, are regulated by the type III secretion regulators HrpX and HrpG and the global regulator Clp
pehA transcription is greatly induced by polygalacturonic acid and positively regulated by Clp (cAMP receptor protein-like protein) and RpfF (an enoyl-CoA hydratase homologue which is required for the synthesis of cis-11-methyl-2-dodecenoic acid, a low-molecular-mass diffusible signal factor)