Molecular and cellular mechanisms of photoperiod- and thermo-sensitive genic male sterility in plants.

Photoperiod- and thermo-sensitive genic male sterile (P/TGMS) lines display male sterility under high-temperature/long-day light conditions and male fertility under low-temperature/short-day light conditions. P/TGMS lines are the fundamental basis for the two-line hybrid breeding, which has notably increased the yield potential and grain quality of rice cultivars. In this review, we focus on the research progress on photoperiod- and thermo-sensitive genic male sterility in plants.

New insights into the evolution and function of the UMAMIT (USUALLY MULTIPLE ACIDS MOVE IN AND OUT TRANSPORTER) gene family.

UMAMIT proteins have been known as key players in amino acid transport. In Arabidopsis, functions of several UMAMITs have been characterized, but their precise mechanism, evolutionary history and functional divergence remain elusive. In this study, we conducted phylogenetic analysis of the UMAMIT gene family across key species in the evolutionary history of plants, ranging from algae to angiosperms.

The Residual Activity of Fatty Acyl-CoA Reductase Underlies Thermo-Sensitive Genic Male Sterility in Rice.

Photoperiod/thermo-sensitive genic male sterility (P/TGMS) is critical for rice two-line hybrid system. Previous studies showed that slow development of pollen is a general mechanism for sterility-to-fertility conversion of TGMS in Arabidopsis. However, whether this mechanism still exists in rice is unknown.

Polymeric phenylpropanoid derivatives crosslinked by hydroxyl fatty acids form the core structure of rape sporopollenin.

Sporopollenin, a critical innovation in the evolution of terrestrial plants, is the core building brick for the outer wall of land-plant spores and pollen. Despite its significance, the basic structure of sporopollenin remains elusive due to its extreme chemical inertness. In this study, we used ethanolamine to completely dissolve rape sporopollenin and successfully identified a total of 22 components, including fatty acids, p-coumaric acid, sterols and polymeric phenylpropanoid derivatives.

The regulatory mechanism of rapid lignification for timely anther dehiscence.

Anther dehiscence is a crucial event in plant reproduction, tightly regulated and dependent on the lignification of the anther endothecium. In this study, we investigated the rapid lignification process that ensures timely anther dehiscence in Arabidopsis. Our findings reveal that endothecium lignification can be divided into two distinct phases.

Temperature and light reverse the fertility of rice P/TGMS line ostms19 via reactive oxygen species homeostasis.

P/TGMS (Photo/thermo-sensitive genic male sterile) lines are crucial resources for two-line hybrid rice breeding. Previous studies revealed that slow development is a general mechanism for sterility-fertility conversion of P/TGMS in Arabidopsis. However, the difference in P/TGMS genes between rice and Arabidopsis suggests the presence of a distinct P/TGMS mechanism in rice.

ZmMS1/ZmLBD30-orchestrated transcriptional regulatory networks precisely control pollen exine development.

Because of its significance for plant male fertility and, hence, direct impact on crop yield, pollen exine development has inspired decades of scientific inquiry. However, the molecular mechanism underlying exine formation and thickness remains elusive. In this study, we identified that a previously unrecognized repressor, ZmMS1/ZmLBD30, controls proper pollen exine development in maize.

Stepwise changes in flavonoids in spores/pollen contributed to terrestrial adaptation of plants.

Protecting haploid pollen and spores against UV-B light and high temperature, 2 major stresses inherent to the terrestrial environment, is critical for plant reproduction and dispersal. Here, we show flavonoids play an indispensable role in this process. First, we identified the flavanone naringenin, which serves to defend against UV-B damage, in the sporopollenin wall of all vascular plants tested.

Arabidopsis pollen-specific glycerophosphodiester phosphodiesterase-like genes are essential for pollen tube tip growth.

In angiosperms, pollen tube growth is critical for double fertilization and seed formation. Many of the factors involved in pollen tube tip growth are unknown. Here, we report the roles of pollen-specific GLYCEROPHOSPHODIESTER PHOSPHODIESTERASE-LIKE (GDPD-LIKE) genes in pollen tube tip growth.

Ascorbic acid-mediated reactive oxygen species homeostasis modulates the switch from tapetal cell division to cell differentiation in Arabidopsis.

The major antioxidant L-ascorbic acid (AsA) plays important roles in plant growth, development, and stress responses. However, the importance of AsA concentration and the regulation of AsA metabolism in plant reproduction remain unclear. In Arabidopsis (Arabidopsis thaliana) anthers, the tapetum monolayer undergoes cell differentiation to support pollen development.

An EPFL peptide signaling pathway promotes stamen elongation via enhancing filament cell proliferation to ensure successful self-pollination in Arabidopsis thaliana.

Proper stamen filament elongation is essential for plant self-pollination and reproduction. Several phytohormones such as jasmonate and gibberellin play important roles in controlling filament elongation, but other endogenous signals involved in this developmental process remain unknown. We report here that three EPIDERMAL PATTERNING FACTOR-LIKE (EPFL) family peptides, EPFL4, EPFL5 and EPFL6, act redundantly to promote stamen filament elongation via enhancing filament cell proliferation in Arabidopsis thaliana.

Ethylene Activates the -/EIL1 Signaling Pathway in Tapetum and Disturbs Anther Development in .

Ethylene was previously reported to repress stamen development in both cucumber and . Here, we performed a detailed analysis of the effect of ethylene on anther development. After ethylene treatment, stamens but not pistils display obvious developmental defects which lead to sterility.

Mutation of glucose-methanol-choline oxidoreductase leads to thermosensitive genic male sterility in rice and Arabidopsis.

Thermosensitive genic male sterility (TGMS) lines serve as the major genetic resource for two-line hybrid breeding in rice. However, their unstable sterility under occasional low temperatures in summer highly limits their application. In this study, we identified a novel rice TGMS line, ostms18, of cultivar ZH11 (Oryza sativa ssp.

AtNusG, a chloroplast nucleoid protein of bacterial origin linking chloroplast transcriptional and translational machineries, is required for proper chloroplast gene expression in Arabidopsis thaliana.

In Escherichia coli, transcription-translation coupling is mediated by NusG. Although chloroplasts are descendants of endosymbiotic prokaryotes, the mechanism underlying this coupling in chloroplasts remains unclear. Here, we report transcription-translation coupling through AtNusG in chloroplasts.

Documenting the Sporangium Development of the Polypodiales Fern .

Reconstructing the development of sporangia in seed-free vascular plants provides crucial information about key processes enabling the production of spores that are important in the life cycle of these plants. By applying fluorescence imaging in intact tissues using dyes and confocal microscopy, this study aimed to reconstruct the key steps during the development of sporangia. Special emphasis was taken on the cell wall structures of tapetum and spore mother cells that have been challenged by microscopical documentation in the past.

AtRsmD Is Required for Chloroplast Development and Chloroplast Function in .

AtRsmD was recently demonstrated to be a chloroplast methyltransferase (MTase) for the mG915 modification in Arabidopsis. Here, its function of AtRsmD for chloroplast development and photosynthesis was further analyzed. The gene is highly expressed in green photosynthetic tissues.

Delayed callose degradation restores the fertility of multiple P/TGMS lines in Arabidopsis.

Photoperiod/temperature-sensitive genic male sterility (P/TGMS) is widely applied for improving crop production. Previous investigations using the reversible male sterile (rvms) mutant showed that slow development is a general mechanism for restoring fertility to P/TGMS lines in Arabidopsis. In this work, we isolated a restorer of rvms-2 (res3), as the male sterility of rvms-2 was rescued by res3.

Development of Refractive Parameters in 3- to 6-Year-Old Children and Its Application in Myopia Prediction and Intervention Guidance.

Objective: To investigate refractive development and prevalence of myopia in children aged 3-6 years in Hebei Province, China, and to explore the developmental law of refraction, so as to clinically guide the prediction and intervention of myopia.

Methods: In May 2019, a total of 6120 people were inspected in 68 kindergartens in 11 cities in Hebei Province. Child refractive refraction was checked under noncycloplegia using a handheld binocular vision screener (SW-800, SUOER, Tianjin, China).

A Novel Chloroplast Protein RNA Processing 8 Is Required for the Expression of Chloroplast Genes and Chloroplast Development in .

Chloroplast development involves the coordinated expression of both plastids- and nuclear-encoded genes in higher plants. However, the underlying mechanism still remains largely unknown. In this study, we isolated and characterized an mutant with an albino lethality phenotype named ().

The GA-DELLA-OsMS188 module controls male reproductive development in rice.

Pollen protects male sperm and allows flowering plants to adapt to diverse terrestrial environments, thereby leading to the rapid expansion of plants into new regions. The process of anther/pollen development is coordinately regulated by internal and external factors including hormones. Currently, the molecular mechanisms underlying gibberellin (GA)-mediated male reproductive development in plants remain unknown.

Slow development allows redundant genes to restore the fertility of rpg1, a TGMS line in Arabidopsis.

Slow development has been shown to be a general mechanism to restore the fertility of thermo-sensitive and photoperiod-sensitive genic male sterile (TGMS and PGMS) lines in Arabidopsis. rpg1 is a TGMS line defective in primexine, which is essential for pollen wall pattern formation. Here, we showed that RPG1-GFP was highly expressed in microsporocytes, microspores, and pollen grains but not in the tapetum in the complemented transgenic line, suggesting that microsporocytes are the main sporophytic cells for primexine formation.

Tapetal 3-Ketoacyl-Coenzyme A Synthases Are Involved in Pollen Coat Lipid Accumulation for Pollen-Stigma Interaction in .

Pollen coat lipids form an outer barrier to protect pollen itself and play essential roles in pollen-stigma interaction. However, the precise molecular mechanisms underlying the production, deposition, regulation, and function of pollen coat lipids during anther development remain largely elusive. In lipid metabolism, 3-ketoacyl-coenzyme A synthases (KCS) are involved in fatty acid elongation or very-long-chain fatty acid (VLCFA) synthesis.