Pectin remodeling belongs to a homeostatic system and triggers transcriptomic and hormonal modulations

Abstract

O_LIHere, we focused on the biological modifications arisen from a strong and transient variation of the pectin methylesterification status during the seed-to-seedling transition. C_LIO_LIA reverse genetic approach was used to trigger specific reduction of pectin de-methylesterification during the seed maturation stage and the related physiological effects were assessed using a combination of biochemical, transcriptomic and microscopic analyses. C_LIO_LIArabidopsis PME36 is required to implement the characteristic pattern of de-methylesterified pectin in the mature seed. While this pattern is strongly impaired in pme36-1 and pme36-2 mature seed, no phenotypical effect is observed in the knockout mutant during seed germination. By analyzing hormone homeostasis and gene expression regulation, we show a strong and dynamic physiological disorder in the mutant, which reveals the existence of a complex compensatory mechanism overcoming the defect in pectin de-methylesterification. C_LIO_LIOur results reveal that pectin methylesterification status acts as upstream modulator involved in an undescribed homeostatic system in which pectin remodeling, hormone signaling and transcriptomic regulations interact to ensure the maintenance of a normal seed-to-seedling developmental program. C_LI