Chromatin-remodeling factor OsINO80 is involved in regulation of gibberellin biosynthesis and is crucial for rice plant growth and development

The phytohormone gibberellin（GA） plays essential roles in plant growth and development. Here,we report that OsINO80, a conserved ATP-dependent chromatin-remodeling factor in rice（Oryza sativa）, functions in both GA biosynthesis and diverse biological processes. OsINO80-knockdown mutants, derived from either T-DNA insertion or RNA interference, display typical GA-deficient phenotypes, including dwarfism, reduced cell length, late flowering, retarded seed germination and impaired reproductive development. Consistently, transcriptome analyses reveal that OsINO80 knockdown results in downregulation by more than two-fold of over 1,000 genes, including the GA biosynthesis genes CPS_1 and GA_3ox_2, and the dwarf phenotype of OsINO80-knockdown mutants can be rescued by the application of exogenous GA3. Chromatin immunoprecipitation（Ch IP） experiments show that OsINO80 directly binds to the chromatin of CPS1 and GA_3ox_2 loci. Biochemical assays establish that OsINO80 specially interacts with histone variant H_2A.Z and the H_2A.Z enrichments at CPS_1 and GA_3ox_2 are decreased in OsINO80-knockdown mutants. Thus, our study identified a rice chromatin-remodeling factor,OsINO80, and demonstrated that OsINO80 is involved in regulation of the GA biosynthesis pathway and plays critical functions for many aspects of rice plant growth and development.

The cytochrome P450 superfamily: Key players in plant development and defense

The cytochrome P450 （CYP） superfamily is the largest enzymatic protein family in plants, and it also widely exists in mammals, fungi, bacteria, insects and so on. Members of this superfamily are involved in multiple metabolic pathways with distinct and complex functions, playing important roles in a vast array of reactions. As a result, numerous secondary metabolites are synthesized that function as growth and developmental signals or protect plants from various biotic and abiotic stresses. Here, we summarize the characterization of CYPs, as well as their phylogenetic classification. We also focus on recent advances in elucidating the roles of CYPs in mediating plant growth and development as well as biotic and abiotic stresses responses, providing insights into their potential utilization in plant breeding.

Functions of Nitrogen,Phosphorus and Potassium in Energy Status and Their Influences on Rice Growth and Development

Nitrogen(N),phosphorus(P)and potassium(K)are important essential nutrients for plant growth and development,but their functions in energy status remains unclear.Here,we grew Nipponbare rice seedlings in a growth chamber for 20 d at 30℃/24℃day/night)under natural sunlight conditions with different nutrient regimes.The results showed that N had the strongest influence on the plant growth and development,followed by P and K.The highest nonstructural carbohydrate content,dry matter weight,net photosynthetic rate(Pn),ATP content,as well as NADH dehydrogenase,cytochrome oxidase and ATPase activities were found in the plants that received sufficient N,P and K.The lowest values of these parameters were detected in the N-deficient plants.Higher dry matter accumulation was observed in the K-deficient than in the P-deficient treatments,but there was no significant difference in the ratio of respiration rate to Pn between these two treatments,suggesting that differences in energy production efficiency may have accounted for this result.This hypothesis was confirmed by higher ATP contents and activities of NADH dehydrogenase,cytochrome oxidase and ATPase in the K-deficient plants than in the P-deficient plants.We therefore inferred different abilities in energy production efficiency among N,P and K in rice seedlings,which determined rice plant growth and development.

Interplay of phytohormones and epigenetic regulation:A recipe for plant development and plasticity

Both phytohormone signaling and epigenetic mechanisms have long been known to play crucial roles in plant development and plasticity in response to ambient stimuli.Indeed,diverse signaling pathways mediated by phytohormones and epigenetic processes integrate multiple upstream signals to regulate various plant traits.Emerging evidence indicates that phytohormones and epigenetic processes interact at multiple levels.In this review,we summarize the current knowledge of the interplay between phytohormones and epigenetic processes from the perspective of phytohormone biology.We also review chemical regulators used in epigenetic studies and propose strategies for developing novel regulators using multidisciplinary approaches.

Plant plasma membrane-resident receptors:Surveillance for infections and coordination for growth and development

As sessile organisms, plants are exposed to pathogen invasions and environmental fluctuations. To overcome the challenges of their surroundings, plants acquire the potential to sense endogenous and exogenous cues, resulting in their adaptability. Hence, plants have evolved a large collection of plasma membrane-resident receptors, including RECEPTOR-LIKE KINASEs(RLKs) and RECEPTOR-LIKE PROTEINs(RLPs) to perceive those signals and regulate plant growth,development, and immunity. The ability of RLKs and RLPs to recognize distinct ligands relies on diverse categories of extracellular domains evolved. Co-regulatory receptors are often required to associate with RLKs and RLPs to facilitate cellular signal transduction. RECEPTOR-LIKE CYTOPLASMIC KINASEs(RLCKs) also associate with the complex, bifurcating the signal to key signaling hubs, such as MITOGEN-ACTIVATED PROTEIN KINASE(MAPK) cascades, to regulate diverse biological processes. Here, we discuss recent knowledge advances in understanding the roles of RLKs and RLPs in plant growth, development, and immunity, and their connection with co-regulatory receptors, leading to activation of diverse intracellular signaling pathways.

Multiple functions of the vacuole in plant growth and fruit quality

Vacuoles are organelles in plant cells that play pivotal roles in growth and developmental regulation.The main functions of vacuoles include maintaining cell acidity and turgor pressure,regulating the storage and transport of substances,controlling the transport and localization of key proteins through the endocytic and lysosomal-vacuolar transport pathways,and responding to biotic and abiotic stresses.Further,proteins localized either in the tonoplast(vacuolar membrane)or inside the vacuole lumen are critical for fruit quality.In this review,we summarize and discuss some of the emerging functions and regulatory mechanisms associated with plant vacuoles,including vacuole biogenesis,vacuole functions in plant growth and development,fruit quality,and plant-microbe interaction,as well as some innovative research technology that has driven advances in the field.Together,the functions of plant vacuoles are important for plant growth and fruit quality.The investigation of vacuole functions in plants is of great scientific significance and has potential applications in agriculture.

Integration and scaling of UV-B radiation effects on plants: the relative sensitivity of growth forms and interspecies interactions

Aims the relative plant type sensitivity and selected community interac-tions under increased UV-B radiation where examined.Specifically,we investigated:(i)if there are differences among growth forms in regard to their sensitivity to UV-B radiation,(ii)if increased UV-B radiation influences the plant competitive balance in plant com-munities and(iii)the response mechanisms of the UV-B radiation-sensitive species that might increase their fitness.Methods to answer our research questions,we used a mechanistic model that,for the first time,integrated the effects of increased UV-B radia-tion from molecular level processes,whole plant growth and devel-opment,and community interactions.Important Findings In the model simulations,species types exhibited different levels of sensitivity to increased UV-B radiation.Summer C3 and C4 annuals showed similar growth inhibition rates,while biennials and winter C3 annuals were the most sensitive.Perennials exhibited inhibitions in growth only if increased UV-B radiation results in increases in metabolic rates.In communities,species sensitive to UV-B radiation may have a competitive disadvantage compared to resistant plant species.But,sensitive species may have a wide array of responses that can increase their fitness and reproductive success in the com-munity,such as,increased secondary metabolites production,changes in timing of emergence and reproduction,and changes in seed size.While individual plants may exhibit significant inhibi-tions in growth and development,in communities,these inhibitions can be mitigated by small morphological and physiological adap-tations.Infrequent or occasional increased UV-B radiation events should not have any lasting effect on the structure of the commu-nity,unless other environmental factors are perturbing the dynamic equilibrium.

Plant target of rapamycin signaling network:Complexes,conservations,and specificities

Target of rapamycin(TOR)is an evolutionarily conserved protein kinase that functions as a central signaling hub to integrate diverse internal and external cues to precisely orchestrate cellular and organismal physiology.During evolution,TOR both maintains the highly conserved TOR complex compositions,and cellular and molecular functions,but also evolves distinctive roles and strategies to modulate cell growth,proliferation,metabolism,survival,and stress responses in eukaryotes.Here,we review recent discoveries on the plant TOR signaling network.We present an overview of plant TOR complexes,analyze the signaling landscape of the plant TOR signaling network from the upstream signals that regulate plant TOR activation to the downstream effectors involved in various biological processes,and compare their conservation and specificities within different biological contexts.Finally,we summarize the impact of dysregulation of TOR signaling on every stage of plant growth and development,from embryogenesis and seedling growth,to flowering and senescence.

Active DNA demethylation in plants:20 years of discovery and beyond

Maintaining proper DNA methylation levels in the genome requires active demethylation of DNA.However,removing the methyl group from a modified cytosine is chemically difficult and therefore,the underlying mechanism of demethylation had remained unclear for many years.The discovery of the first eukaryotic DNA demethylase,Arabidopsis thaliana REPRESSOR OF SILENCING 1(ROS1),led to elucidation of the 5-methylcytosine base excision repair mechanism of active DNA demethylation.In the 20 years since ROS1 was discovered,our understanding of this active DNA demethylation pathway,as well as its regulation and biological functions in plants,has greatly expanded.These exciting developments have laid the groundwork for further dissecting the regulatory mechanisms of active DNA demethylation,with potential applications in epigenome editing to facilitate crop breeding and gene therapy.

Mitogen-activated protein kinase cascades in plant signaling

Mitogen-activated protein kinase(MAPK)cascades are key signaling modules downstream of receptors/sensors that perceive either endogenously produced stimuli such as peptide ligands and damage-associated molecular patterns(DAMPs)or exogenously originated stimuli such as pathogen/microbe-associated molecular patterns(P/MAMPs),pathogen-derived effectors,and environmental factors.In this review,we provide a historic view of plant MAPK research and summarize recent advances in the establishment of MAPK cascades as essential components in plant immunity,response to environmental stresses,and normal growth and development.Each tier of the MAPK cascades is encoded by a small gene family,and multi ple members can function redundantly in an MAPK cascade.Yet,they carry out a diverse array of biological functions in plants.How the signaling specificity is achieved has become an interesting topic of MAPK research.Future investigations into the molecular mechanism(s)underlying the regulation of MAPK activation including the activation kinetics and magnitude in response to a stimulus,the spatiotemporal expression patterns of all the components in the signaling pathway,and functional characterization of novel MAPK substrates are central to our understanding of MAPK functions and signaling specificity in plants.

Advances in proteome-wide analysis of plant lysine acetylation

Lysine acetylation(LysAc)is a conserved and important post-translational modification(PTM)that plays a key role in plant physiological and metabolic processes.Based on advances in Lys-acetylated protein immunoenrichment and mass-spectrometric technology,LysAc proteomics studies have been performed in many species.Such studies have made substantial contributions to our understanding of plant LysAc,revealing that Lys-acetylated histones and nonhistones are involved in a broad spectrum of plant cellular processes.Here,we present an extensive overview of recent research on plant Lys-acetylproteomes.We provide in-depth insights into the characteristics of plant LysAc modifications and the mechanisms by which LysAc participates in cellular processes and regulates metabolism and physiology during plant growth and development.First,we summarize the characteristics of LysAc,including the properties of Lys-acetylated sites,the motifs that flank Lys-acetylated lysines,and the dynamic alterations in LysAc among different tissues and developmental stages.We also outline a map of Lys-acetylated proteins in the Calvin–Benson cycle and central carbon metabolism–related pathways.We then introduce some examples of the regulation of plant growth,development,and biotic and abiotic stress responses by LysAc.We discuss the interaction between LysAc and Na-terminal acetylation and the crosstalk between LysAc and other PTMs,including phosphorylation and succinylation.Finally,we propose recommendations for future studies in the field.We conclude that LysAc of proteins plays an important role in the regulation of the plant life cycle.