Detection and localization of pectin methylesterase isoforms in pollen tubes of Nicotiana tabacum L.

Li, Yiqin; Mareck, Alain; Faleri, Claudia; Moscatelli, Alessandra; Liu, Qiang; Cresti, Mauro

doi:10.1007/s004250100664

Cited by 88 publications

(78 citation statements)

References 42 publications

(61 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These observations are in close agreement with the findings of Li et al (2002) who show with immunogold transmission electron microscopy that PME is only found on the inner layer of the apical cell wall in tobacco pollen tubes and is not distributed throughout the thickness of the wall. Together, these findings suggest that PME-GFP is either degraded or diffuses away relatively quickly.…”

Section: Secretion Of Pme-gfp In Tobacco Pollen Tubes Oscillates and supporting

confidence: 93%

“…We feel this assumption is warranted since we do not see PME-GFP fluorescence extending out into the wall. In addition, previous work by Li et al (2002), using immunogold localization of PME, found the enzyme only on the inner layer of the cell wall. From these considerations, we conclude that the changes in PME-GFP fluorescence are directly proportional to the rate of exocytosis.…”

Section: Discussion Exocytosis Oscillates and Leads The Increase In Gmentioning

confidence: 83%

“…For example, following exocytosis, the pectin, which is initially 20 to 30% deesterified, becomes increasingly deesterified by PME, and cross-linked by Ca 2+ , in a process that rigidifies and possibly compacts the wall (Willats et al, 2001;. Additionally, the deesterification reaction yields methanol and protons; the former likely diffuses away quickly, while the latter could locally affect the cell wall pH and associated enzymes, such as PME itself (Moustacas et al, 1986;Li et al, 2002). These interactions will affect wall structure; however, we do not think that they account for the observations we report.…”

Section: Wall Thickness and Pi Fluorescence Are Valid Estimates Of Thmentioning

confidence: 99%

“…The homogalacturonans are synthesized as methyl-esters in the Golgi apparatus (O'Neill et al, 1990;Staehelin and Moore, 1995; and are secreted as such Sterling et al, 2001). The enzyme pectin methyl esterase (PME), which is also secreted (Li et al, 2002;Tian et al, 2006), catalyzes the deesterification of the homogalacturonans and exposes carboxyl residues, which are cross-linked by Ca 2+ , leading to gel formation and a stiffening of the cell wall (Catoire et al, 1998;. Rhamnogalacturonan II residues, which are covalently incorporated into the homogalacturonan chains, also contribute to cell wall structure through the formation of borate diol-esters (Ishii et al, 1999;O'Neill et al, 2001;O'Neill et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Exocytosis Precedes and Predicts the Increase in Growth in Oscillating Pollen Tubes

et al. 2009

View full text Add to dashboard Cite

We examined exocytosis during oscillatory growth in lily (Lilium formosanum and Lilium longiflorum) and tobacco (Nicotiana tabacum) pollen tubes using three markers: (1) changes in cell wall thickness by Nomarski differential interference contrast (DIC), (2) changes in apical cell wall fluorescence in cells stained with propidium iodide (PI), and (3) changes in apical wall fluorescence in cells expressing tobacco pectin methyl esterase fused to green fluorescent protein (PME-GFP). Using PI fluorescence, we quantified oscillatory changes in the amount of wall material from both lily and tobacco pollen tubes. Measurement of wall thickness by DIC was only possible with lily due to limitations of microscope resolution. PME-GFP, a direct marker for exocytosis, only provides information in tobacco because its expression in lily causes growth inhibition and cell death. We show that exocytosis in pollen tubes oscillates and leads the increase in growth rate; the mean phase difference between exocytosis and growth is -988 6 38 in lily and -1248 6 48 in tobacco. Statistical analyses reveal that the anticipatory increase in wall material predicts, to a high degree, the rate and extent of the subsequent growth surge. Exocytosis emerges as a prime candidate for the initiation and regulation of oscillatory pollen tube growth.

show abstract

Section: Secretion Of Pme-gfp In Tobacco Pollen Tubes Oscillates and supporting

confidence: 93%

Section: Discussion Exocytosis Oscillates and Leads The Increase In Gmentioning

confidence: 83%

Section: Wall Thickness and Pi Fluorescence Are Valid Estimates Of Thmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Exocytosis Precedes and Predicts the Increase in Growth in Oscillating Pollen Tubes

et al. 2009

View full text Add to dashboard Cite

show abstract

“…The finding that unesterified and methyl-esterified pectin epitopes localize in the tip of the wall supports the hypothesis that pectins are polymerized and esterified within the Golgi complex and then transported and deposited in the growing wall by secretory vesicles (Li et al, 1995;Li et al, 1997). After deposition, the esterified pectins become progressively de-esterified by the action of pectin methyltransferases (PME) leading to a more rigid form of pectin in the mature pollen wall by crosslink with Ca 2+ ions and boric acid (Carpita and Gibeaut, 1993;Li et al, 1997;Li et al, 2002;Holdaway-Clarke et al, 2003). The deposition of the secondary wall starts later and increases gradually in thickness back from the tip.…”

Section: B a D Cmentioning

confidence: 57%

Gametophyte interaction and sexual reproduction: how plants make a zygote

Boavida¹,

Vieira²,

Becker³

et al. 2005

Int. J. Dev. Biol.

View full text Add to dashboard Cite

The evolutionary success of higher plants relies on a very short gametophytic phase, which underlies the sexual reproduction cycle. Sexual plant reproduction takes place in special organs of the flower: pollen, the male gametophyte, is released from the anthers and then adheres, grows and interacts along various tissues of the female organs, collectively known as the pistil. Finally, it fertilizes the female gametophyte, the embryo sac. Pollen is released as bi or tricellular, highly de-hydrated and presumably containing all the biochemical components and transcripts to germinate. Upon hydration on the female tissues, it develops a cytoplasmic extension, the pollen tube, which is one of the fastest growing cells in nature. Pollen is completely "ready-to-go", but despite this seemingly simple reaction, very complex interactions take place with the female tissues. In higher animals, genetic mechanisms for sex determination establish striking developmental differences between males and females. In contrast, most higher plant species develop both male and female structures within the same flower, allowing self-fertilization. Outcrossing is ensured by self-incompatibility mechanisms, which evolved under precise genetic control, controlling self-recognition and cell-to-cell interaction. Equally important is pollen selection along the female tissues, where interactions between different cell types with inherent signalling properties correspond to check-points to ensure fertilization. Last but not least, pollen-pistil interaction occurs in a way that enables the correct targeting of the pollen tubes to the receptive ovules. In this review, we cover the basic mechanisms underlying sexual plant reproduction, from the structural and cellular determinants, to the most recent genetic advances.

show abstract

Proteomic analyses ofOryza sativa mature pollen reveal novel proteins associated with pollen germination and tube growth

Dai¹,

Li²,

Chen³

et al. 2006

Proteomics

163

253

View full text Add to dashboard Cite

As a highly reduced organism, pollen performs specialized functions to generate and carry sperm into the ovule by its polarily growing pollen tube. Yet the molecular genetic basis of these functions is poorly understood. Here, we identified 322 unique proteins, most of which were not reported previously to be in pollen, from mature pollen of Oryza sativa L. ssp japonica using a proteomic approach, 23% of them having more than one isoform. Functional classification reveals that an overrepresentation of the proteins was related to signal transduction (10%), wall remodeling and metabolism (11%), and protein synthesis, assembly and degradation (14%), as well as carbohydrate and energy metabolism (25%). Further, 11% of the identified proteins are functionally unknown and do not contain any conserved domain associated with known activities. These analyses also identified 5 novel proteins by de novo sequencing and revealed several important proteins, mainly involved in signal transduction (such as protein kinases, receptor kinase-interacting proteins, guanosine 5'-diphosphate dissociation inhibitors, C2 domain-containing proteins, cyclophilins), protein synthesis, assembly and degradation (such as prohibitin, mitochondrial processing peptidase, putative UFD1, AAA+ ATPase), and wall remodeling and metabolism (such as reversibly glycosylated polypeptides, cellulose synthase-like OsCsLF7). The study is the first close investigation, to our knowledge, of protein complement in mature pollen, and presents useful molecular information at the protein level to further understand the mechanisms underlying pollen germination and tube growth.

show abstract

Detection and localization of pectin methylesterase isoforms in pollen tubes of Nicotiana tabacum L.

Cited by 88 publications

References 42 publications

Exocytosis Precedes and Predicts the Increase in Growth in Oscillating Pollen Tubes

Exocytosis Precedes and Predicts the Increase in Growth in Oscillating Pollen Tubes

Gametophyte interaction and sexual reproduction: how plants make a zygote

Proteomic analyses ofOryza sativa mature pollen reveal novel proteins associated with pollen germination and tube growth

Contact Info

Product

Resources

About