Synchronization of Arabidopsis flowering time and vegetative growth stage via FT overexpression can reveal inherent heterosis due to heterozygosity in intraspecific hybrids.

Intraspecific hybrids of Arabidopsis sometimes display heterosis. However, allelic variation of flowering repressor genes causes late flowering in F1, which might distort the potential heterosis effect due to prolonged vegetative growth. Here, overexpression of flowering gene FT synchronized flowering and eliminated growth differentials between parental and F1.

Application of Green-enhanced Nano-lantern as a bioluminescent ratiometric indicator for measurement of Arabidopsis thaliana root apoplastic fluid pH.

Plant root absorbs water and nutrients from the soil, and the root apoplastic fluid (AF) is an important intermediate between cells and the surrounding environment. The acid growth theory suggests that an acidic AF is needed for cell wall expansion during root growth. However, technical limitations have precluded the quantification of root apoplastic fluid pH (AF-pH).

A novel petal up-regulated promoter analysis in by using bioluminescence reporter gene.

Flower opening is an important phenomenon in plant that indicates the readiness of the flower for pollination leading to petal expansion and pigmentation. This phenomenon has great impact on crop yield, which makes researches of its mechanism attractive for both plant physiology study and agriculture. Gene promoters directing the expression in petal during the petal cell wall modification and expansion when flower opens could be a convenient tool to analyze or monitor gene expression targeting this event.

Enhanced brightness of bacterial luciferase by bioluminescence resonance energy transfer.

Using the lux operon (luxCDABE) of bacterial bioluminescence system as an autonomous luminous reporter has been demonstrated in bacteria, plant and mammalian cells. However, applications of bacterial bioluminescence-based imaging have been limited because of its low brightness. Here, we engineered the bacterial luciferase (heterodimer of luxA and luxB) by fusion with Venus, a bright variant of yellow fluorescent protein, to induce bioluminescence resonance energy transfer (BRET).

Cullin1-P is an Essential Component of Non-Self Recognition System in Self-Incompatibility in Petunia.

Self-incompatibility (SI) in flowering plants is a genetic reproductive barrier to distinguish self- and non-self pollen to promote outbreeding. In Solanaceae, self-pollen is rejected by the ribonucleases expressed in the styles (S-RNases), via its cytotoxic function. On the other side, the male-determinant is the S-locus F-box proteins (SLFs) expressed in pollen.

Calcium signalling mediates self-incompatibility response in the Brassicaceae.

Self-incompatibility in the Brassicaceae is controlled by multiple haplotypes encoding the pollen ligand (S-locus protein 11, SP11, also known as S-locus cysteine-rich protein, SCR) and its stigmatic receptor (S-receptor kinase, SRK). A haplotype-specific interaction between SP11/SCR and SRK triggers the self-incompatibility response that leads to self-pollen rejection, but the signalling pathway remains largely unknown. Here we show that Ca(2+) influx into stigma papilla cells mediates self-incompatibility signalling.

Gene duplication and genetic exchange drive the evolution of S-RNase-based self-incompatibility in Petunia.

Self-incompatibility (SI) systems in flowering plants distinguish self- and non-self pollen to prevent inbreeding. While other SI systems rely on the self-recognition between specific male- and female-determinants, the Solanaceae family has a non-self recognition system resulting in the detoxification of female-determinants of S-ribonucleases (S-RNases), expressed in pistils, by multiple male-determinants of S-locus F-box proteins (SLFs), expressed in pollen. It is not known how many SLF components of this non-self recognition system there are in Solanaceae species, or how they evolved.

Ubiquitin-proteasome-mediated degradation of S-RNase in a solanaceous cross-compatibility reaction.

Many plants have a self-incompatibility (SI) system in which the rejection of self-pollen is determined by multiple haplotypes at a single locus, termed S. In the Solanaceae, each haplotype encodes a single ribonuclease (S-RNase) and multiple S-locus F-box proteins (SLFs), which function as the pistil and pollen SI determinants, respectively. S-RNase is cytotoxic to self-pollen, whereas SLFs are thought to collaboratively recognize non-self S-RNases in cross-pollen and detoxify them via the ubiquitination pathway.

A pollen coat-inducible autoinhibited Ca2+-ATPase expressed in stigmatic papilla cells is required for compatible pollination in the Brassicaceae.

In the Brassicaceae, intraspecific non-self pollen (compatible pollen) can germinate and grow into stigmatic papilla cells, while self-pollen or interspecific pollen is rejected at this stage. However, the mechanisms underlying this selective acceptance of compatible pollen remain unclear. Here, using a cell-impermeant calcium indicator, we showed that the compatible pollen coat contains signaling molecules that stimulate Ca(2+) export from the papilla cells.

Cytoplasmic Ca2+ changes dynamically during the interaction of the pollen tube with synergid cells.

The directional growth of the pollen tube from the stigma to the embryo sac in the ovules is regulated by pollen-pistil interactions based on intercellular communication. Although pollen tube growth is regulated by the cytoplasmic Ca(2+) concentration ([Ca(2+)](cyt)), it is not known whether [Ca(2+)](cyt) is involved in pollen tube guidance and reception. Using Arabidopsis expressing the GFP-based Ca(2+)-sensor yellow cameleon 3.

Collaborative non-self recognition system in S-RNase-based self-incompatibility.

Self-incompatibility in flowering plants prevents inbreeding and promotes outcrossing to generate genetic diversity. In Solanaceae, a multiallelic gene, S-locus F-box (SLF), was previously shown to encode the pollen determinant in self-incompatibility. It was postulated that an SLF allelic product specifically detoxifies its non-self S-ribonucleases (S-RNases), allelic products of the pistil determinant, inside pollen tubes via the ubiquitin-26S-proteasome system, thereby allowing compatible pollinations.

Fine-tuning of the cytoplasmic Ca2+ concentration is essential for pollen tube growth.

Pollen tube growth is crucial for the delivery of sperm cells to the ovule during flowering plant reproduction. Previous in vitro imaging of Lilium longiflorum and Nicotiana tabacum has shown that growing pollen tubes exhibit a tip-focused Ca(2+) concentration ([Ca(2+)]) gradient and regular oscillations of the cytosolic [Ca(2+)] ([Ca(2+)](cyt)) in the tip region. Whether this [Ca(2+)] gradient and/or [Ca(2+)](cyt) oscillations are present as the tube grows through the stigma (in vivo condition), however, is still not clear.

Design of peptide inhibitors for the importin alpha/beta nuclear import pathway by activity-based profiling.

Despite the current availability of selective inhibitors for the classical nuclear export pathway, no inhibitor for the classical nuclear import pathway has been developed. Here we describe the development of specific inhibitors for the importin alpha/beta pathway using a novel method of peptide inhibitor design. An activity-based profile was created via systematic mutational analysis of a peptide template of a nuclear localization signal.

Actin dynamics in papilla cells of Brassica rapa during self- and cross-pollination.

The self-incompatibility system of the plant species Brassica is controlled by the S-locus, which contains S-RECEPTOR KINASE (SRK) and S-LOCUS PROTEIN11 (SP11). SP11 binding to SRK induces SRK autophosphorylation and initiates a signaling cascade leading to the rejection of self pollen. However, the mechanism controlling hydration and germination arrest during self-pollination is unclear.

Calcium crystals in the anther of Petunia: the existence and biological significance in the pollination process.

Using an X-ray microanalysis system fitted with variable-pressure scanning electron microscopy, we noted that many calcium crystals accumulated under the stomium in the anther of Petunia. When the anther was dehisced and pollen grains were released from the stomata, the calcium crystals adhered to pollen grains and moved to the stigma together with pollen grains. In contrast, an X-ray microanalysis of the stigma surface before pollination detected no calcium emission on the stigma surface.

Comparative analysis of the self-incompatibility (S-) locus region of Prunus mume: identification of a pollen-expressed F-box gene with allelic diversity.

Background: Self-incompatibility (SI) in the Solanaceae, Rosaceae and Scrophulariaceae is gametophytically controlled by a single polymorphic locus, termed the S-locus. To date, the only known S-locus product is a polymorphic ribonuclease, termed S-RNase, which is secreted by stylar tissue and thought to act as a cytotoxin that degrades the RNA of incompatible pollen tubes. However, understanding how S-RNase causes S-haplotype specific inhibition of pollen tubes has been hampered by the lack of a cloned pollen S-determinant gene.

The dominance of alleles controlling self-incompatibility in Brassica pollen is regulated at the RNA level.

Self-incompatibility (SI) in Brassica is controlled sporophytically by the multiallelic S-locus. The SI phenotype of pollen in an S-heterozygote is determined by the relationship between the two S-haplotypes it carries, and dominant/recessive relationships often are observed between the two S-haplotypes. The S-locus protein 11 (SP11, also known as the S-locus cysteine-rich protein) gene has been cloned from many pollen-dominant S-haplotypes (class I) and shown to encode the pollen S-determinant.