S-sulfenylation-mediated inhibition of the GSNOR1 activity regulates ovule development in Arabidopsis.

Reactive oxygen species (ROS) and nitric oxide (NO) are two critical classes of signaling molecules that regulate plant development and stress responses. The intracellular level of S-nitrosoglutathione (GSNO), a major bioactive NO species, is regulated by the highly conserved GSNO reductase (GSNOR). However, the molecular mechanisms underlying ROS-mediated regulation of GSNOR remain largely unclear.

MpMLO1 controls sperm discharge in liverwort.

In bryophytes, sexual reproduction necessitates the release of motile sperm cells from a gametophyte into the environment. Since 1856, this process, particularly in liverworts, has been known to depend on water. However, the molecular mechanism underlying this phenomenon has remained elusive.

Pollen-expressed RLCKs control pollen tube burst.

In angiosperms, the pollen tube enters the receptive synergid cell, where it ruptures to release its cytoplasm along with two sperm cells. This interaction is complex, and the exact signal transducers that trigger the bursting of pollen tubes are not well understood. In this study, we identify three homologous receptor-like cytoplasmic kinases (RLCKs) expressed in pollen tubes of Arabidopsis, Delayed Burst 1/2/3 (DEB1/2/3), which play a crucial role in this process.

Dual-mode tunable absorber based on quasi-bound states in the continuum.

In this Letter, we propose a novel, to the best of our knowledge, dual-mode tunable absorber that utilizes quasi-bound states in the continuum (q-BIC) based on the periodically arranged silicon cylinders tetramer. By introducing asymmetry perturbation through manipulating the diameters of diagonal cylinders in the all-dielectric structure, the symmetry-protected BIC (SP-BIC) transforms into q-BIC, leading to the emergence of one transmission and one reflection Fano-like resonant mode. The relationship between the quality factor of each mode and the asymmetry parameter α is analyzed, revealing an exponential dependence with an exponent of -1.

Central-cell-produced attractants control fertilization recovery.

Animal fertilization relies on hundreds of sperm racing toward the egg, whereas, in angiosperms, only two sperm cells are delivered by a pollen tube to the female gametes (egg cell and central cell) for double fertilization. However, unsuccessful fertilization under this one-pollen-tube design can be detrimental to seed production and plant survival. To mitigate this risk, unfertilized-gamete-controlled extra pollen tube entry has been evolved to bring more sperm cells and salvage fertilization.

Osmoregulation determines sperm cell geometry and integrity for double fertilization in flowering plants.

Distinct from the motile flagellated sperm of animals and early land plants, the non-motile sperm cells of flowering plants are carried in the pollen grain to the female pistil. After pollination, a pair of sperm cells are delivered into the embryo sac by pollen tube growth and rupture. Unlike other walled plant cells with an equilibrium between internal turgor pressure and mechanical constraints of the cell walls, sperm cells wrapped inside the cytoplasm of a pollen vegetative cell have only thin and discontinuous cell walls.

POD1-SUN-CRT3 chaperone complex guards the ER sorting of LRR receptor kinases in Arabidopsis.

Protein sorting in the secretory pathway is essential for cellular compartmentalization and homeostasis in eukaryotic cells. The endoplasmic reticulum (ER) is the biosynthetic and folding factory of secretory cargo proteins. The cargo transport from the ER to the Golgi is highly selective, but the molecular mechanism for the sorting specificity is unclear.

Nucleolar histone deacetylases HDT1, HDT2, and HDT3 regulate plant reproductive development.

Nucleolus is a membrane-less organelle where ribosomes are assembled, and ribosomal RNAs (rRNAs) transcribed and processed. The assembled ribosomes composed of ribosomal proteins and rRNAs synthesize proteins for cell survival. In plants, the loss of nucleolar ribosomal proteins often causes gametophytically or embryonically lethality.

Boosting the photocatalytic hydrogen evolution performance of monolayer CN coupled with MoSiN: density-functional theory calculations.

Very recently, an important two-dimensional material, MoSiN, was successfully synthesized. However, pure MoSiN has some inherent shortcomings when used in photocatalytic water splitting to produce hydrogen, especially a low separation rate of photogenerated electron-hole pairs and a poor visible light response. Interestingly, we find that the MoSiN can be used as a good modification material, and it can be coupled with CN to form an efficient heterojunction photocatalyst.

Central Cell in Flowering Plants: Specification, Signaling, and Evolution.

During the reproduction of animals and lower plants, one sperm cell usually outcompetes the rivals to fertilize a single egg cell. But in flowering plants, two sperm cells fertilize the two adjacent dimorphic female gametes, the egg and central cell, respectively, to initiate the embryo and endosperm within a seed. The endosperm nourishes the embryo development and is also the major source of nutrition in cereals for humankind.

Plasma membrane H -ATPases-mediated cytosolic proton gradient regulates pollen tube growth.

The polar growth of pollen tubes is essential for the delivery of sperm cells during fertilization in angiosperms. How this polar growth is regulated has been a long-standing question. An in vitro pharmacological assay previously implicated proton flux in pollen tube growth, although genetic and cellular supporting evidence was lacking.

Transcriptional repression specifies the central cell for double fertilization.

Double fertilization is a key innovation for the evolutionary success of angiosperms by which the two fertilized female gametes, the egg cell and central cell, generate the embryo and endosperm, respectively. The female gametophyte (embryo sac) enclosed in the sporophyte is derived from a one-celled haploid cell lineage. It undergoes successive events of mitotic divisions, cellularization, and cell specification to give rise to the mature embryo sac, which contains the two female gametes accompanied by two types of accessory cells, namely synergids and antipodals.

Integration of ovular signals and exocytosis of a Ca channel by MLOs in pollen tube guidance.

The spatiotemporal regulation of Ca channels at the plasma membrane in response to extracellular signals is critical for development, stress response and reproduction, but is poorly understood. During flowering-plant reproduction, pollen tubes grow directionally to the ovule, which is guided by ovule-derived signals and dependent on Ca dynamics. However, it is unknown how ovular signals are integrated with cytosolic Ca dynamics in the pollen tube.

TICKET attracts pollen tubes and mediates reproductive isolation between relative species in Brassicaceae.

In flowering plants, pollen tubes are attracted to the ovule by secreted peptides to release the sperm cells for double fertilization. This process is species-specific and acts as an important stage of reproductive isolation between species. Here we identified a cysteine-rich peptide TICKET2 in Arabidopsis thaliana and its orthologs in Arabidopsis lyrata and Capsella rebella that can attract the conspecific pollen tubes, but not the pollen tubes of relative species in Brassicaceae.

Maternal control of suspensor programmed cell death via gibberellin signaling.

Plant embryos are generated and develop in a stable and well-protected microenvironment surrounded by maternal tissue, which is vital for embryogenesis. However, the signaling mechanisms responsible for maternal tissue-to-proembryo communication are not well understood. Here, we report a pathway for maternal tissue-to-proembryo communication.

Both male and female gametogenesis require a fully functional protein S-acyl transferase 21 in Arabidopsis thaliana.

S-Acylation is a reversible post-translational lipid modification in which a long chain fatty acid covalently attaches to specific cysteine(s) of proteins via a thioester bond. It enhances the hydrophobicity of proteins, contributes to their membrane association and plays roles in protein trafficking, stability and signalling. A family of Protein S-Acyl Transferases (PATs) is responsible for this reaction.

LOT regulates TGN biogenesis and Golgi structure in plants.

Trans-Golgi Network (TGN) is an essential organelle in eukaryotic cells. It acts not only as the sorting station of trafficking cargoes, but also as a signaling hub. In plant cells, TGN simultaneously takes the role of early endosome (EE) and contributes to the endocytic recycling.

Golgi-localized LOT regulates -Golgi network biogenesis and pollen tube growth.

The -Golgi network (TGN) is an essential tubular-vesicular organelle derived from the Golgi and functions as an independent sorting and trafficking hub within the cell. However, the molecular regulation of TGN biogenesis remains enigmatic. Here we identified an mutant loss of TGN () that is defective in TGN formation and sterile due to impaired pollen tube growth in the style.

Ligands Switch Model for Pollen-Tube Integrity and Burst.

In flowering plants, pollen tubes deliver and release the immotile sperms to the female gametes for fertilization, but mechanisms remain unclear. New results show that the RALF family peptides control pollen-tube integrity and burst by binding to CrRLK1L family receptors and cell wall leucine-rich repeat extensins.