the isoforms EINV1, EINV2, EINV3 and EINV4 have the same molecular mass and catalytic properties such as Km for sucrose, pH optimum and temperature optimum, but they exhibit significant difference in pI values, thermal stability and chemical reactivity. The observed differences between isoforms arise from posttranslational modifications
isoforms VINV1 plays an important role in sucrose unloading and starch accumulation, as well in buffering the pools of sucrose, hexoses and sugar phosphates in leaves, specifically at later stages of plant development
isoforms VINV2 plays an important role in sucrose unloading and starch accumulation, as well in buffering the pools of sucrose, hexoses and sugar phosphates in leaves, specifically at later stages of plant development
ectopic overexpression of invertase inhibitor INVINH1 in Arabidopsis thaliana specifically reduces cell wall invertase activity. By contrast, silencing its expression in tomato significantly increases the activity of cell wall invertase without altering activities of cytoplasmic and vacuolar invertases. Elevation of cell wall invertase activity in RNA interference transgenic tomato leads to a prolonged leaf life span involving in a blockage of abscisic acid-induced senescence and an increase in seed weight and fruit hexose level
INV-E is associated with the development of the photosynthetic apparatus and the assimilation of nitrogen in Arabidopsis seedlings to control the ratio of sucrose content to hexose content
loss-of-function mutation in cell wall invertase INCW2 gene Mn1 results in the miniature1 seed phenotype. In wild-type seed, walls in growth develop uniformly in the basal endosperm transfer cell layer during 7 to 17 d after pollination, and the secretory/endocytic organelles proliferate in the basal endosperm transfer cells. Mitochondria accumulate in the vicinity of walls in growth. In the mutant basal endosperm transfer cells, walls in growth are stunted and their endoplasmic reticulum is swollen, Golgi density in the mutant basal endosperm transfer cells is 51% of the wild-type Golgi density. However, the polarized distribution of mitochondria is not affected
single T-DNA insertion mutants of cytosolic isoforms cinv1 and cinv2 appear identical to wild-type plants on soil under our growth conditions. The cinv1/cinv2 double mutant plants flower and set seed when grown on soil, but are much smaller in all respects than wild-type plants at maturity. Seedlings of cinv1/cinv2 double mutant have relatively normal shoot growth, but drastically reduced root growth on solid medium without sugar. Whereas primary root extension over 7 days of growth is 60% of the wild-type value in cinv1 mutant, and 120% of the wild-type value in cinv2, it is only 17% of the wild-type value in cinv1/cinv2 double mutants. Cells in the root expansion zone of cinv1/cinv2 mutants are enlarged and have a greater tendency to collapse during manipulation than those of wild-type and single-mutant plants. Abnormal cell divisions occur in the stele, endodermis, and cortex. Growth on glucose restores root extension in double mutants to approximately half of wild-type. Neutral invertase activity in roots is 40% lower in double mutant than in wild-type seedlings
T-DNA insertion lines of cell wall invertase 4 do not produce nectar. Overall nectary morphology appears to be normal, but mutant flowers accumulate higher than normal levels of starch in the receptacle, but not within the nectaries themselves. Conversely, wild-type, but not mutant, nectarial stomata stain intensely for starch. Cell wall extracts prepared from mutant flowers display greatly reduced invertase activity when compared with wild-type plants, and mutant flowers also accumulate significantly lower levels of total soluble sugar
invertases are important for gall development in clubroot disease of Brassicaceae caused by Plasmodiophora brassicae. Different transgenic lines expressing an invertase inhibitor under the control of two root-specific promoters, Pyk10 and CrypticT80, which results in the reduction of invertase activity, show clearly reduced clubroot symptoms in root tissue with highest promoter expression, whereas hypocotyl galls develop normally
high invertase activity of, and increased sucrose import into, young tomato fruit can contribute to their heat tolerance through increasing sink strength and sugar signalling activities, possibly regulating a programmed cell death pathway
post-translational regulation of acid invertase by the vacuolar invertase inhibitor 2 is an important component of resistance to cold-induced sweetening
the enzyme isoform CWIN1 plays a role in nuclear division but not cell wall biosynthesis in endosperm, as well as early seed development, particularly in regulating endosperm nuclear division, embryonic provascular formation, and transfer cell differentiation
compared to invertase InvA, invertase InvB possesses a much higher catalytic activity. The higher activity may be responsible for the vital role of InvB in heterocyst development and nitrogen fixation
in the root tips, the activity of the vacuolar and cell wall-bound invertases increases markedly under water stress resulting in the accumulation of hexoses (glucose and fructose) that contributes significantly to osmotic adjustment. A transient rise in hydrogen peroxide (H2O2) precedes the enhancement of invertases upon exposure to osmotic stress. H2O2 probably generated by a NADPH oxidase is required as a signalling molecule for the up-regulation of the vacuolar invertase activity in the root tips under osmotic stress, thereby enhancing the capacity for osmotic adjustment
the enzyme has a critical role in floral organ development and male and female fertilities. The enzyme is required to synchronize style and stamen development. Reduction of GhVIN expression in the seed coat as the major cause for the reduced female fertility
ZmMRP-1 is a key regulator of the differentiation of endosperm. The absence of cell wall invertase activity is a major inductive signal of the ZmMRP-1 expression
ZmMRP-1 is a key regulator of the differentiation of endosperm. The absence of cell wall invertase activity is a major inductive signal of the ZmMRP-1 expression