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G2-like (GLK) transcription factors contribute significantly and extensively in regulating chloroplast growth and development in plants. This study investigated the genome-wide identification, phylogenetic relationships, conserved motifs, promoter cis-elements, MCScanX, divergence times, and expression profile analysis of PeGLK genes in moso bamboo (Phyllostachys edulis). Overall, 78 putative PeGLKs (PeGLK1–PeGLK78) were identified and divided into 13 distinct subfamilies. Each subfamily contains members displaying similar gene structure and motif composition. By synteny analysis, 42 orthologous pairs and highly conserved microsynteny between regions of GLK genes across moso bamboo and maize were found. Furthermore, an analysis of the divergence times indicated that PeGLK genes had a duplication event around 15 million years ago (MYA) and a divergence happened around 38 MYA between PeGLK and ZmGLK. Tissue-specific expression analysis showed that PeGLK genes presented distinct expression profiles in various tissues, and many members were highly expressed in leaves. Additionally, several PeGLKs were significantly up-regulated under cold stress, osmotic stress, and MeJA and GA treatment, implying that they have a likelihood of affecting abiotic stress and phytohormone responses in plants. The results of this study provide a comprehensive understanding of the moso bamboo GLK gene family, as well as elucidating the potential functional characterization of PeGLK genes. [ABSTRACT FROM AUTHOR]

Drought is one of the most serious environmental stresses. Plant AT-rich sequence and zinc-binding (PLATZ) proteins perform indispensable functions to regulate plant growth and development and to respond to environmental stress. In this present study, we identified PhePLATZ1 in moso bamboo and found that its expression was up-regulated in response to 20% PEG-6000 and abscisic acid (ABA) treatments. Next, transgenic PhePLATZ1 -overexpressing Arabidopsis lines were generated. Overexpression of PhePLATZ1 improved drought stress resistance of transgenic plants by mediating osmotic regulation, enhancing water retention capacity and reducing membrane and oxidative damage. These findings were corroborated by analysing physiological indicators including chlorophyll, relative water content, leaf water loss rate, electrolyte leakage, H 2 O 2 , proline, malondialdehyde content and the enzyme activities of peroxidase and catalase. Subsequent seed germination and seedling root length experiments that included exposure to exogenous ABA treatments showed that ABA sensitivity decreased in transgenic plants relative to wild-type plants. Moreover, transgenic PhePLATZ1 -overexpressing plants promoted stomatal closure in response to ABA treatment, suggesting that PhePLATZ1 might play a positive regulatory role in the drought resistance of plants via the ABA signaling pathway. In addition, the transgenic PhePLATZ1 -OE plants showed altered expression of some stress-related genes when grown under drought conditions. Taken together, these findings improve our understanding of the drought response of moso bamboo and provide a key candidate gene for the molecular breeding of this species for drought tolerance. • The expression level of PhePLATZ1 in moso bamboo was induced by drought and ABA. • Overexpression of PhePLATZ1 improved drought stress tolerance of Arabidopsis. • Transgenic Arabidopsis showed the decreased ABA-sensitivity during seed germination and early seedling growth. • Transgenic Arabidopsis promoted stomatal closure in response to ABA treatment. • PhePLATZ1 regulated the expression of several stress-related genes under drought stress. [ABSTRACT FROM AUTHOR]

Acclimation to hypoxia and anoxia is important in various ecological systems, especially flooded soil. Phyllostachys pracecox is sensitive to flooding, and therefore, it is important to explore ways of alleviating hypoxia stress in the roots. In this study, we investigated the regulatory effect of spermidine (Spd) on flooded P. praecox seedlings. A batch experiment was carried out in roots treated with Spd under flooding for eight days. The following factors were subsequently measured: growth, survival rate, root respiratory activity, soluble protein and anaerobic respiration enzyme contents (pyruvate decarboxylase, PDC; alcohol dehydrogenase, ADH; lactate dehydrogenase, LDH; alanine aminotransferase, AlaAT), S-adenosylmethionine decarboxylase (SAMDC), nitrate reductase (NR), ACC oxidase (ACO) and ACC synthetase (ACS) activities, free Spd, spermine (Spm) and the diamine precursor putrescine (Put) content, indole-3-acetic acid (IAA) and abscisic acid (ABA) content, ethylene emissions and expression of hormone-related genes. Application of Spd promoted root growth (root length, volume, surface and dry weight) and root respiratory inhibition, improved the soluble protein content, and reduced the O 2 ·- production rate, H 2 O 2 and MDA content to alleviate the damage of roots under flooding. A significant increase in SAMDC activity, and ABA and IAA contents were also observed, along with a reduction in ethylene emissions, NR, ACO and ACS activities (p < 0.05). Exogenous Spd increased the free Spd and Spm contents in the P. praecox roots, but decreased the free Put content. Taken together, these findings suggest that hypoxia stress was alleviated. Moreover, exogenous Spd up-regulated the expression of auxin-related genes ARF1 , AUX1 , AUX2 , AUX3 and AUX4 , and down-regulated the expression of ethylene-related ACO and ACS genes during flooding. In addition, correlation and RDA analysis showed that ARF1 , ACO and ACS significantly promoted the expression of auxin, ACO and ACS enzyme activities, respectively (p < 0.05), while ADH, NR, AlaAT, ethylene emissions, Put, Spd, ACS and ACO were significantly correlated with ACS , ACO , and auxin-related gene expression (p < 0.05). Overall, ethylene emissions, ACS and ACO were identified as the main drivers of ethylene and auxin-related gene structure. These results suggest that Spd regulated hormone concentrations, the content of Spd, Spm and Put, and related gene expression, in turn regulating physiological changes such as anaerobic enzyme activity, mitigating flooding stress in the roots and improving overall growth. Spd therefore has the potential to improve the adaptability of P. praecox to flooding stress. • The crosstalk of and hormone triggers hormone-related genes expression under flooding. • Spd increases anaerobic respiration enzyme activity in roots under flooding. • Spd improves aerobic metabolism and promote root growth under flooding. • The analysis showed ETH, ACS and ACO were identified as the main drivers of hormone-related gene structure. [ABSTRACT FROM AUTHOR]

Sheath blades are the first bamboo organ exposed to sunlight after shoots initially emerge. However, it remains uncertain whether sheath blades affect bamboo shoot growth and quality. Accordingly, this study explores variations in Phyllostachys violascens shoot growth and quality, comparing natural growth conditions to periodic sheath blade removal treatments. Results show that sheath blade removal and interactions between sheath blade removal and duration had no significant effect on the morphology, protein nutritional quality, or value of bamboo shoots. However, the length of bamboo shoot was significantly lower 4 d after treatment compared to 4 d after natural growth conditions. Moreover, sheath blade removal did have a significant effect on soluble sugar, total acid, oxalic acid, tannic acid, and cellulose content as well as sugar–acid ratios of bamboo shoots, while having no significant effect on the content and proportion of amino acid flavor compounds. Interactions between sheath blade removal and duration only had a significant effect on total acid and sugar–acid ratios. Soluble sugar, oxalic acid, tannic acid, and sugar–acid ratios increased significantly 2 d after sheath blade removal, while total acid and cellulose content decreased significantly. Lastly, soluble sugar content and sugar–acid ratios increased significantly 4 d after sheath blade removal. Findings from this study indicate that sheath blades affect shoot quality, particularly taste, which is mainly driven by carbon metabolism, but the effect of nitrogen metabolism was not obvious. This study gave a new perspective for revealing the formation mechanism of shoot quality, and also provided possible methods of improvement for the shoot quality. [ABSTRACT FROM AUTHOR]

Root-associated bacteria play a major role in plant health and productivity. However, how organic amendment influences root-associated bacteria is uncertain in Lei bamboo (Phyllostachys praecox) plantations. Here, we compared the rhizosphere and endophytic microbiomes in two Lei bamboo plantations with (IMS) and without (TMS) the application of organic amendment for 16 years. The results showed IMS significantly increased (p < 0.05) the relative abundance of Proteobacteria and significantly decreased (p < 0.05) the relative abundance of Acidobacteria, Bacteroidetes, and Verrucomicrobiota. The root endophytic Proteobacteria and Acidobacteria were significantly higher in abundance (p < 0.05) in the IMS than in the TMS, while Actinobacteria and Firmicutes were significantly lower in abundance. Five taxa were assigned to Proteobacteria and Acidobacteria, which were identified as keystones in the rhizosphere soil microbiome, while two species taxonomically affiliated with Proteobacteria were identified as keystones in the root endophytic microbiota, indicating this phylum can be an indicator for a root-associated microbiome in response to IMS. The soil pH, soil total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), available potassium (AK), and TOC:TP ratio were significantly correlated (p < 0.05) with the bacterial community composition of both rhizosphere soils and root endophytes. TMS increased the microbial network complexity of root endophytes but decreased the microbial network complexity of rhizosphere soil. Our results suggest IMS shapes the rhizosphere and endophytic bacterial community compositions and their interactions differently, which should be paid attention to when designing management practices for the sustainable development of forest ecosystems. [ABSTRACT FROM AUTHOR]

Plants employ an array of photoprotection mechanisms to alleviate the harmful effects of high light intensity. The violaxanthin cycle, which is associated with non-photochemical quenching (NPQ), involves violaxanthin de-epoxidase (VDE), and zeaxanthin epoxidase (ZEP) and is one of the most rapid and efficient mechanisms protecting plants under high light intensity. Woody bamboo is a class of economically and ecologically important evergreen grass species widely distributed in tropical and subtropical areas. However, the function of VDE in bamboo has not yet been elucidated. In this study, we found that high light intensity increased NPQ and stimulated the de-epoxidation of violaxanthin cycle components in moso bamboo (Phyllostachys edulis), whereas, samples treated with the VDE inhibitor (dithiothreitol) exhibited lower NPQ capacity, suggesting that violaxanthin cycle plays an important role in the photoprotection of bamboo. Further analysis showed that not only high light intensity but also extreme temperatures (4 and 42°C) and drought stress upregulated the expression of PeVDE in bamboo leaves, indicating that PeVDE is induced by multiple abiotic stresses. Overexpression of PeVDE under the control of the CaMV 35S promoter in Arabidopsis mutant npq1 mutant could rescue its NPQ, indicating that PeVDE functions in dissipating the excess absorbed light energy as thermal energy in bamboo. Moreover, compared with wildtype (Col-0) plants, the transgenic plants overexpressing PeVDE displayed enhanced photoprotection ability, higher NPQ capacity, slower decline in the maximum quantum yield of photosystem II (Fv/Fm) under high light intensity, and faster recovery under optimal conditions. These results suggest that PeVDE positively regulates the response to high light intensity in bamboo plants growing in the natural environment, which could improve their photoprotection ability through the violaxanthin cycle and NPQ. [ABSTRACT FROM AUTHOR]

Keywords: bamboo strips; Iosipescu; shear properties; stress-strain curves EN bamboo strips Iosipescu shear properties stress-strain curves 765 780 16 08/09/22 20220801 NES 220801 1 Introduction Engineered bamboo (EB) structures based on the structural laminate made with bamboo strips/fibers have been fast-developed recently ([4]; [11]; [22]; [40]; [41]). Graph: Figure 1: Engineered bamboo panels for glubam structures and their shear-dominated failure: (a) bamboo strips used for engineered bamboo panels; (b) shear-dominated failure of glubam members. Although the bamboo nodes have an apparent reinforcement influence on the interlaminar fracture properties of bamboo strips, as discussed in [44], the bamboo nodes have a minor influence on the overall stress-displacement performance of bamboo strips in this study. [Extracted from the article]

Resource sharing among connected ramets (i.e. clonal integration) is one of the distinct traits of clonal plants. Clonal integration confers Moso bamboo (Phyllostachys pubescens) a strong adaptability to different environmental conditions. But the mechanisms of how clonal integration makes Moso bamboo has better performance are still poorly understood. In this study, acropetal and basipetal translocation of photosynthates between Moso bamboo ramets were analyzed separately to investigate how clonal fragments obtain higher benefits under heterogeneous N conditions. Clonal fragments of Moso bamboo consisting of two interconnected mother–daughter ramets were used, each of the ramets was subjected to either with or without N addition. The acropetal and basipetal translocation of 13C-photosynthates was separated via single-ramet 13CO2-labeling. Mother ramets translocated more 13C-photosynthates to daughter ramets with N addition, and the translocation of 13C-photosynthates to mother ramets was more pronounced when daughter ramets were treated with N addition. The 13C-photosynthates that were translocated from mother ramets without and with N addition were mainly invested in the leaves and roots of daughter ramets with N addition, from daughter ramets with N addition were mainly invested in the leaves and roots of mother ramets with and without N addition, respectively. These results suggest that mother ramets preferentially invest more resources in nutrient-rich daughter ramets, and that daughter ramets serve as efficient resource acquisition sites to specialize in acquiring abundant resources based on the resource conditions of mother ramets. Clonal plants can improve their resource acquisition efficiency and maximize the overall performance in this way. [ABSTRACT FROM AUTHOR]

Simple Summary: Moso bamboo (Phyllostachys edulis) expansion caused substantial changes in the ecosystem process. Changes in plant–soil chemical characteristics and microbial community compositions have not been thoroughly studied. To understand changes in forest ecosystem process and the underlining microbial community compositions, we studied changes in plant–soil chemical characteristics and microbial community compositions. The results showed that moso bamboo expansion into Japanese cedar plantations altered litter C:N and divergently affected soil fungal and bacterial community compositions. Specifically, moso bamboo expansion decreased soil organic carbon, total nitrogen, litter carbon, and the carbon to nitrogen ratio. Moso bamboo expansion also increased soil NH4+-N and pH, while it decreased fungi OTUs at the phyla, class, order, family, and genus levels. The expansion of moso bamboo into Japanese cedar substantially altered soil-fungal- and bacterial-community structure, which might have implications for changes in the ecosystem element-cycling process. Moso bamboo expansion is common across the world. The expansion of moso bamboo into adjacent forests altered plant and soil characteristics. While the community structure of soil fungi and bacteria plays an important role in maintaining the function of forest ecosystems, changes in microbial community compositions remain unclear, limiting our understanding of ecological process changes following moso bamboo expansion. To explore changes in the community structure of soil fungi and bacteria in Japanese cedar plantations experiencing expansion of moso bamboo, Illumina NovaSeq high-throughput sequencing technology was used to elucidate changes in soil microbial communities as well as alteration in litter and soil chemical characteristics. The results showed that moso bamboo expansion decreased content of soil organic carbon, total nitrogen, litter carbon, and the carbon to nitrogen ratio as well as the number of bacterial operational taxonomic units (OTUs) at the genus level, the α-diversity Simple index, and the abundance of Acidobacteria, Chloroflexi, and Gemmatimonadetes. Moso bamboo expansion also increased soil NH4+-N, pH, while it decreased fungi OTUs at the phyla, class, order, family, and genus level. The expansion of moso bamboo into Japanese cedar substantially altered soil fungal and bacterial community structure, which might have implications for changes in the ecosystem element-cycling process. In the forest ecosystem and expansion management of moso bamboo, the types and different expansion stages of moso bamboo should be paid attention to, in the assessment of ecological effects and soil microbial structure. [ABSTRACT FROM AUTHOR]

Bamboo (Bambusoideae) belongs to the grass family (Poaceae) and has been utilized as one of the most important nontimber forest resources in the world. Moso bamboo (Phyllostachys edulis) is a large woody bamboo with high ecological and economic values. Global climate change brings potential challenges to the normal growth of moso bamboo, and hence its production. Despite the release of moso bamboo genome sequence, the knowledge on genome-wide responses to abiotic stress is still limited. In this study, we generated a transcriptome data set with respect to dehydration and cold responses of moso bamboo using RNA-seq technology. The differentially expressed genes (DEGs) under treatments of dehydration and cold stresses were identified. By combining comprehensive gene ontology (GO) analysis, time-series analysis, and co-expression analysis, candidate genes involved in dehydration and cold responses were identified, which encode abscisic acid (ABA)/water deficit stress (WDS)-induced protein, late embryogenesis abundant (LEA) protein, 9-cis-epoxycarotenoid dioxygenase (NCED), anti-oxidation enzymes, transcription factors, etc. Additionally, we used PeLEA14, a dehydration-induced gene encoding an "atypical" LEA protein, as an example to validate the function of the identified stress-related gene in tolerance to abiotic stresses, such as drought and salt. In this study, we provided a valuable genomic resource for future excavation of key genes involved in abiotic stress responses and genetic improvement of moso bamboo to meet the requirement for environmental resilience and sustainable production. [ABSTRACT FROM AUTHOR]

Summary: Bamboo has a natural anisotropic porous structure. Previous studies have shown strong correlations between the properties and microstructure of bamboo. In this study, we examined the microstructure of Moso bamboo to reveal the mechanism of enhanced properties with tung oil thermal treatment. The morphological and chemical microstructure of Moso bamboo were characterized using scanning electron microscopy (SEM) and Raman spectroscopy. We found that tung oil film presented in the cell wall, cell lumen, and intercellular space after tung oil thermal treatment, which could decrease the water permeability in the cell wall. Additionally, the pits in vessels showed significant shrinkage in the short-axis orientation with thermal treatment in tung oil, and the shrinkage rate was nearly 50% with a temperature of tung oil over 140°C, which prevented the transportation of water through the pit. The content of tung oil in bamboo was reduced by more than 50% with an increase of tung oil temperature from 140°C to 200°C, which further supported the results of changed bamboo morphology. Altogether, these findings offer further support for the enhanced hydrophobic property of bamboo after tung oil thermal treatment. [ABSTRACT FROM AUTHOR]

In the present study, we surveyed the ascomycetes from bamboo of Phyllostachys across Sichuan Province, China. A biphasic approach based on morphological characteristics and multigene phylogeny confirmed seven species, including one new genus, two new species, and five new host record species. A novel genus Paralloneottiosporina is introduced to accommodate Pa. sichuanensis that was collected from leaves of Phyllostachys violascens. Moreover, the newly introduced species Bifusisporella sichuanensis was isolated from leaves of P. edulis, and five species were newly recorded on bamboos, four species belonging to Apiospora, viz. Ap. yunnana, Ap. neosubglobosa, Ap. jiangxiensis, and Ap. hydei, and the last species, Seriascoma yunnanense, isolated from dead culms of P. heterocycla. Morphologically similar and phylogenetically related taxa were compared. Comprehensive descriptions, color photo plates of micromorphology are provided. [ABSTRACT FROM AUTHOR]

It's appropriate mechanical behavior and its low carbon footprint allow bamboo to replace conventional construction materials in various applications. Currently, it should be considered that there are countries that still do not have sufficient knowledge about the structural characteristics of locally grown bamboos. In this sense, this research presents the results for the determination of the geometric properties and the compressive and tensile mechanical properties parallel to the fiber of the species Phyllostachys aurea from the Ecuadorian Amazon. With the samples tested, the compressive strength parallel to the fiber presented a minimum standard deviation in the results, showing an average strength of 52.4 MPa. After a statistical analysis of these values, a normal distribution was observed between them, increasing their reliability; the tensile strength parallel to the fiber showed a high standard deviation in the results, due to the difficulty in preparing the required sample as established in the standard ISO/FDIS - 22157 (2019). However, the average resistance of this parameter was 90.2 MPa, confirming that it is a bamboo with great potential against this type of load. Therefore, a comparison was made between the compressive and tensile strength of the Phyllostachys aurea species with other conventional materials used in construction such as reinforced concrete, structural steel and Guadua angustifolia Kunth bamboo. [ABSTRACT FROM AUTHOR]

Background: Development of Pantana phyllostachysae, a moso bamboo pest, is affected by its diet. Understanding the mechanism underlying the different insect-resistant capacities of on- and off-year moso bamboo fed by P. phyllostachysae is crucial for managing pest outbreaks. As microbes were proven to influence plant immunity, we compared gut microbial communities of P. phyllostachysae with different diets by metabarcoding sequencing. By using sterilization assay, microbes were removed from leaf surfaces, and thus we confirmed that microbes inhabiting moso bamboo leaves impact the weight of P. phyllostachysae larva. Furthermore, the gut microbial communities of P. phyllostachysae fed on on- and off-year bamboo leaves were compared, to identify the functional microbial communities that impact the interaction between bamboo leaves and P. phyllostachysae. Results: We found that species from orders Lactobacillales and Rickettsiales are most effective within functional microbiota. Functional prediction revealed that gut microbes of larva fed on on-year leaves were related to naphthalene degradation, while those fed on off-year leaves were related to biosynthesis of ansamycins, polyketide sugar unit biosynthesis, metabolism of xenobiotics, and tetracycline biosynthesis. Most functional microbes are beneficial to the development of larva that feed on on-year bamboo leaves, but damage the balance of intestinal microenvironment and immune systems of those larva that feed on off-year leaves. Conclusions: This work developed an efficient strategy for microbiome research of Lepidopteran insects and provided insights into microbiota related to the interaction between host plants and P. phyllostachysae. We provided microbial candidates for the ecological control of P. phyllostachysae according to the function of effective microbiota. [ABSTRACT FROM AUTHOR]

The nucleosome assembly protein 1 (NAP1) family is the main histone chaperone of histone H2A–H2B. To explore the function of NAP1 family genes in moso bamboo (Phyllostachys edulis), characterized by extremely rapid growth and a long flowering cycle, we originally conducted a genome-wide analysis of the PheNAP1 gene. The phylogenetic relationship, gene expression pattern, DNA methylation, and histone modification were analyzed. Eventually, 12 PheNAP1 genes were recognized from the Phyllostachys edulis genome, divided into two sorts: the NRP subfamily (four members) and the NAP subfamily (eight members). Highly conserved motifs exist in each subfamily, which are distinct between subfamilies. PheNAP1 was distributed homogeneously on 10 out of 24 chromosomes, and gene duplication contributed significantly to the enhancement of the PheNAP1 gene in the genome. Cis-acting element analysis showed that PheNAP1 family genes are involved in light, hormone, and abiotic stress responses and may play an important role in the rapid growth and flowering. PheNAP1 exhibited the highest expression level in fast-growing shoots, indicating it is closely associated with the rapid growth of moso bamboo. Besides, PheNAP1 can rescue the early-flowering phenotype of nrp1-1 nrp2-2, and it affected the expression of genes related to the flowering pathway, like BSU1, suggesting the vital role that PheNAP1 may take in the flowering process of moso bamboo. In addition, histone modification results showed that PheNAP1 could bind to phosphorylation-, acetylation-, and methylation-modified histones to further regulate gene expression. A sketch appears: that PheNAP1 can accompany histones to regulate fast-growth- and flowering-related genes in moso bamboo. The consequences of this study enrich the understanding of the epigenetic regulation mechanism of bamboo plants and lays a foundation for further studies on the role of the NAP1 gene in Phyllostachys edulis and the function of chromatin regulation in forest growth and development. [ABSTRACT FROM AUTHOR]

Hypoxia affects plant growth, hormone content, various enzyme activities, cell structure, peroxide production, and metabolic level, therefore reducing crop yield. This study assessed the physiological, biochemical, and metabolic characteristics of Phyllostachys praecox. Results revealed that hypoxia stress treatment significantly inhibited plant growth. Leaf chlorophyll contents was initially improved and then reduced with plant growth time. Under hypoxia stress, the root activity significantly was reduced, leading to the decrease in the nutrient absorption and transport. Yet, with low oxygen concentration, the contents of ethanol, acetaldehyde, and lactic acid were improved. With hypoxia stress, phospholipids and amino acids were the main metabolites of Phyllostachys praecox. Glycosphospholipid metabolism is the key pathway in responding to hypoxia stress significantly (p < 0.05), and lysophosphatidlycholine (lysoPC) and phosphatidylcholines (PC) in the metabolites of this metabolic pathway were significantly enhanced. Our study reveals the mechanism of Phyllostachys praecox cell membrane responding to hypoxia stress based on molecular level. This is conducive to finding targeted solutions to improve the productivity of Phyllostachys praecox to better optimize a mulching approach in the bamboo forest. [ABSTRACT FROM AUTHOR]

Bamboo-cultured cells (BCCs) were produced under three phytohormone conditions. BCC lignin was then isolated and characterized by heteronuclear single-quantum coherence-nuclear magnetic resonance (HSQC-NMR) analysis. HSQC-NMR analysis revealed that all three BCC lignin samples were composed of guaiacyl (G), syringyl (S), oxidized syringyl (S′), and p-hydroxyphenyl (H) units. p-Coumaric acid (pCA) and ferulic acid (FA) were identified as well. Main lignin substructures, including β-O-4, β-5, and β-β, were also detected. However, β-O-4/α-O-4, spirodienone, dibenzodioxocin, or tricin structures were absent in the BCC lignin. The BCC lignin contained higher proportions of H, FA, and β-5 structures, but less proportions of S, S′, and β-O-4 structures than the mature bamboo lignin. The removal of auxin 2,4-dichlorophenoxyacetic acid (2,4-D) from the subculture medium promoted G unit formations. Nevertheless, it suppressed H and pCA unit formations. Cytokinin 6-benzyladenine (BA) promoted H and β-β structure formations as well but suppressed β-O-4 formations than in the mature bamboo and BCC lignin produced under phytohormone free conditions. [ABSTRACT FROM AUTHOR]

Oxidative stress is induced by an imbalanced redox status, and the brain is one of the physical organs particularly weakly to reactive oxygen species (ROS) because of its requirement of high oxygen and abundance of peroxidation-sensitive lipid cells. Many studies have reported that oxidative stress plays a crucial role in the cause of neurodegenerative disorders such as Alzheimer's and Parkinson's disease. Antioxidant therapy has thus been proposed for the prophylaxis and treatment of neurodegenerative diseases. Previously, we reported the pharmacological efficacy of bamboo stems, including hepato-protection and anti-melanogenesis. Albeit, pharmacological efficacies of bamboo stems in neurodegenerative diseases have been unveiled. Therefore, we currently investigated the neuroprotective effect of PN3 (acetate fraction of the 80% ethylalcohol extract of domestic bamboo stems of Phyllostachys nigra variety henonis) in PC12 cells, a rat pheochromocytoma cell line, against oxidative stress-mediated cell injury. Results of this study demonstrated that PN3 could activate nuclear factor erythroid 2-related factor 2 (Nrf2) to counteract the oxidative injuries of PC12 cells. PN3 facilitates the phosphorylation and nuclear translocation of Nrf2 through the AKT/ERK/P38 pathway. Nrf2 activation by PN3 induced Nrf2 downstream antioxidant enzymes, such as heme oxygenase 1, glutamate-cysteine ligase, and NADPH quinone oxidoreductase 1. Moreover, PN3 prevented ROS generation and cell death induced by tert-butyl hydroperoxide. Furthermore, human amyloid beta peptide aggregation was antagonized by PN3 in vitro. Collectively, our results indicate that PN3 provides neuroprotection via Nrf2 activation in PC12 cells. [ABSTRACT FROM AUTHOR]

Hypoxic environments have an adverse effect on the growth and development of P. praecox, and this is accompanied by the production of reducing substances such as Fe and Mn. In this study, the effect of hypoxic stress and Mn concentrations on leaf chlorophyll contents, root morphology, root activity, element absorption, antioxidant enzymes, and respiratory enzyme system of P. praecox were evaluated in a hydroponics environment. The results revealed that application of Mn2+ during hypoxic stress enhanced leaf chlorophyll contents and boosted up the indexes of the root system. The root activity of P. praecox was reduced with stresses of hypoxia. The treatment of Mn2+ initially improved and then decreased the root activity of P. praecox, and attained its maximum with application of 300 μmol/L Mn2+ compared with control. The indexes of antioxidant enzymes of P. praecox were higher than that of 8 mg/L oxygen concentrations except for variable superoxide dismutase (SOD) in the treatment of 300 μmol/L Mn2+ with hypoxia stress. The application of Mn had inhibited the absorption of mineral elements in P. praecox. The activities of pyruvate decarboxylase (PDC), alcohol dehydrogenase (ADH), and lactic dehydrogenase (LDH) were initially improved and then diminished with hypoxia stress. It is concluded that hypoxia is a key factor affecting the growth and degradation of P. praecox, while combining it with the increase of Mn concentration enhances the damage to Phyllostachys pubescens. Our research is helpful for the sustainable management and scientific fertilization management of Phyllostachys praecox. [ABSTRACT FROM AUTHOR]

Height to crown base (HCB) is an important variable used as a predictor of forest growth and yield. This study developed a nonlinear, mixed-effects HCB model through inclusion of plot-level random effects using data from 29 sample plots distributed across a state-owned Yixing forest farm in Jiangsu province, eastern China. Among several predictor variables evaluated in the analyses, bamboo height, canopy density, and total basal area of bamboo with a diameter larger than that of the subject bamboo individual contributed significantly to the HCB variations. The inclusion of random effects improved the prediction accuracy of the model significantly, indicating that the HCB variations within and across the sample plots were substantial. The model was localized using four sampling strategies, and the study identified that using two medium-sized bamboos by diameter at breast height per sample plot resulted in the smallest prediction error. This strategy, which would balance both measurement cost and potential error, may be applied to estimate the random effects and localization of the nonlinear mixed-effects HCB model for moso bamboo in eastern China. [ABSTRACT FROM AUTHOR]

• Increased flavonoids and decreased chlorophyll caused coloration of bamboo leaves. • More than ten flavonoids were identified in yellow-striped bamboo leaves. • The genes involved in flavonoid and chlorophyll metabolism pathways were revealed. • A regulatory module for color variation of bamboo leaves was proposed. Bamboo has a certain proportion of color variation on leaves or stems during natural growth, but the molecular mechanisms of color variation for most bamboo are still scarce. In this study, the leaves during different development stages (NL, IML and ML) of Phyllostachys violascens (Pv, control) and P. violascens var. Flavistriatus (PvF) were used to analyze the regulatory mechanism of leaf coloration by combined transcriptomic and metabolomic sequencing. Compared to the control, PvF leaves showed a significant decrease in chlorophyll (Chl) and an increase in flavonoid levels, resulting in a change in leaf color. According to metabolomic results, the l -glutamic acid was accumulated in PvF leaves, and a correlation analysis with RNA-seq revealed that PvGLK and PvGATA16 may be involved in Chl metabolism in PvF leaves. Further, more than 10 flavonoids were determined to be accumulated in matured PvF leaves. Weighted gene co-expression network analysis (WGCNA) showed several genes strongly correlated to major enriched flavonoids such as rutin and quercetin. Among those, the PvWRKY53 might play crucial roles in controlling flavonoid biosynthesis as well as Chl degradation in PvF leaves. Taken together, our findings demonstrate that a yellow-striped phenotype should be the result of changes in the contents of Chl and flavonoids in PvF. This study will deepen our understanding of color variation and pave the way to improving the ornamental value of bamboo. [Display omitted] [ABSTRACT FROM AUTHOR]

Feruloylated oligosaccharides (FOs) generated by decomposing plant hemicellulose, offer a wide range of potential applications in both the food and biomedical areas. As a graminaceous plant, bamboo is rich in hemicellulose. However, the structural composition and activity studies of FOs from it were rarely reported. In this study, FOs from Phyllostachys acuta (pFOs) obtained by enzymatic hydrolysis were isolated by AmberliteXAD-2 and C18 SPE columns. Then, pFOs were qualitatively and quantitatively analyzed by UPLC-ESI-MS/MS after labeled by 3-Amino-9-ethyl-carbazole (AEC), and the chemical antioxidant activity of pFOs and effects of pFOs on H 2 O 2 -induced oxidative damage were investigated. Finally, 14 of pFOs isomers were distinguished and identified, of which 10 did not contain hexoses and 4 did, and the three most abundant pFO structures were 12 (Iso 7, F1A1X2H2-AEC, 29.04 %), 11 (Iso 6, F1A1X1H2-AEC, 17.96 %), and 4 (Iso 3-1, F1A1X3-AEC, 15.57 %). The results of antioxidant studies showed that pFOs possessed certain reducing power, scavenging DPPH radicals, scavenging superoxide anion radicals, and scavenging hydroxyl radicals. Among them, the ability to clear DPPH radicals was particularly significant. pFOs significantly reduced the viability of RAW264.7 cells after H 2 O 2 induction, whereas pFOs had a significant protective effect (p < 0.001). pFOs increased the viability of T-AOC and SOD enzymes in oxidatively damaged cells, as well as had a significant inhibition effect on ROS elevation (p < 0.001). This study lays the foundation for the structural analysis and antioxidant activity evaluation of bamboo-derived feruloyl oligosaccharides for their application in food and pharmaceutical fields. [Display omitted] • FOs from Phyllostachys acuta (pFOs) obtained by enzymatic hydrolysis were isolated by AmberliteXAD-2 and C18 SPE columns. • pFOs were qualitatively and quantitatively analyzed by UPLC-ESI-MS/MS after labeled by 3-Amino-9-ethyl-carbazole (AEC). • The effects of pFOs on H 2 O 2 -induced oxidative damage in RAW264.7 were investigated. [ABSTRACT FROM AUTHOR]

Woody bamboo exhibits a unique flowering characteristic with a lengthy flowering cycle, often followed by death. In many plant species, alternative splicing (AS) is a common phenomenon involved in controlling flowering. In this study, a PeCOL13 gene in moso bamboo (Phyllostachys edulis) was characterized. It produced two isoforms: PeCOL13α and PeCOL13β, due to an intron-retained AS. The PeCOL13α expressed in the vegetative phase and the reproductive phase, but the PeCOL13β didn't express during the vegetative phase and showed only a weak expression from F1 to F3 during the reproductive phase. Overexpression of PeCOL13α in rice (Oryza sativa) resulted in a delayed heading time through inhibiting the expressions of Hd3a , OsFTL1 , and Ehd1 and activating the expressions of Ghd7 and RCN1. However, the PeCOL13β- overexpressed rice didn't show any significant differences in flowering compared with wild-type (WT), and the expressions of downstream flowering genes had no notable changes. Further analysis revealed that both PeCOL13α and PeCOL13β can bind to the PeFT promoter. Meanwhile, PeCOL13α can inhibit the transcription of PeFT , but PeCOL13β showed no effect. When PeCOL13α and PeCOL13β coexist, the inhibitory effect of PeCOL13α on PeFT transcription was weakened by PeCOL13β. This study provides new insights into the mechanism of bamboo flowering research. • PeCOL13 generates two splice variants through intron-retained alternative splicing. • PeCOL13α and PeCOL13β express differently for the vegetative and flowering phases. • A diversity in flowering function between PeCOL13α and PeCOL13β is caused by AS. • PeCOL13β can reduce the inhibition of PeCOL13α on PeFT , affecting bamboo flowering. [ABSTRACT FROM AUTHOR]

Argonaute (AGO) proteins are the core components of the RNA-induced silencing complexes (RISC) in the cytoplasm and nucleus, and are necessary for the development of plant shoot meristem, which gives rise to the above-ground plant body. In this study, we identified 23 Phyllostachys edulis AGO genes (PhAGOs) that were distributed unequally on the 14 unmapped scaffolds. Gene collinearity and phylogeny analysis showed that the innovation of PhAGO genes was mainly due to dispersed duplication and whole-genome duplication, which resulted in the enlarged PhAGO family. PhAGO genes were expressed in a temporal-spatial expression pattern, and they encoded proteins differently localized in the cytoplasm and/or nucleus. Overexpression of the PhAGO2 and PhAGO4 genes increased the number of tillers or leaves in Oryza sativa and affected the shoot architecture of Arabidopsis thaliana. These results provided insight into the fact that PhAGO genes play important roles in plant development. • The innovation of PhAGO genes were mainly due to dispersed and whole-genome duplication. • PhAGOs with temporal-spatial expression pattern were distributed unequally on the 14 unmapped scaffolds of moso bamboo. • Ectopic expression of PhAGO2 and PhAGO4 affected the shoot architecture of Oryza sativa and Arabidopsis thaliana. [ABSTRACT FROM AUTHOR]

Moso bamboo, recognized for its wide distribution and economic importance, encounters challenges in varietal enhancement owing to its protracted sexual reproduction cycle. This study employed whole-genome resequencing to identify spontaneous mutations in Moso bamboo and investigated mutagenesis using atmospheric and room temperature plasma (ARTP). Through the sequencing results, we identified a population of flowering bamboo as an asexual breeding line. Notably, the flowering Moso bamboo population, exclusively derived from asexual reproduction, exhibited a high spontaneous mutation rate (4.54 × 10−4 to 1.15 × 10−3/bp) during sexual reproduction, considering parental and cross-pollination effects. Genetic disparities between the offspring and parents exhibited a bimodal distribution, indicating a substantial cross-pollination rate. ARTP mutagenesis increased structural variations in offspring, whereas changes in SNPs and INDELs were less pronounced. Sanger sequencing validated the gene subset, providing a foundation for the investigation of spontaneous mutation rates via whole-genome sequencing. These insights, particularly from mutagenized offspring sequencing, can contribute to Moso bamboo breeding strategies. • Identified flowering Moso bamboo as a clonal lineage. • Revealed high spontaneous mutation rate in sexual reproduction of Moso bamboo. • Predicted high cross-pollination rates in Moso bamboo. • ARTP mutagenesis enhances structural variations in Moso bamboo offspring. [ABSTRACT FROM AUTHOR]

The two-component system (TCS) regulates plant growth and stress responses by affecting phytohormone signalling; however, its role in Moso bamboo (Phyllostachys edulis) is poorly understood. Here, we identified 87 Moso bamboo TCS genes (PheTCS s), including 24 that encode PheHKs (histidine kinases), 10 that encode PheHPts (histidine phosphotransfer proteins) and 53 that encode PheRRs (response regulators). The PheTCS s and their corresponding proteins were comprehensively analysed using bioinformatics: this covered their gene structure, conserved motifs, phylogenetic tree, cis-acting elements on promoters, collinearity analysis and transcriptome data. Within 24 h of subjecting Moso bamboo to salt and drought stress, the expression of PheRRB8 increased from 1.2-fold to 6.1-fold and from 8.1-fold to 31.9-fold, respectively. Subcellular localisation and transcriptional activity experiments demonstrated that PheRRB8 localised to the nucleus and cytoplasm and exhibited transactivation activity in yeast. Furthermore, in silico protein interaction predictions indicated that PheRRB8 may interact with most PheHPts. A weighted correlation network analysis centred on PheRRB8 revealed 500 co-expressed genes, which were mostly annotated as 'response to stimulus' in the Gene Ontology database and were enriched in the 'metabolism' pathway in the Kyoto Encyclopedia of Genes and Genomes database. Subsequently, PheRRB8 was overexpressed in Arabidopsis thaliana for functional studies. The phenotype and physiological indexes of PheRRB8 -overexpressing transgenic A. thaliana plants under stress treatment showed that PheRRB8 weakened A. thaliana 's tolerance to salt stress. Our results present the Moso bamboo TCS family more comprehensively to researchers and contribute to the understanding of Moso bamboo's responses to abiotic stresses. [Display omitted] • A total of 87 TCSs were identified in Moso bamboo. • PheRRB8 was screened by bioinformatics analysis and Real-Time PCR experiments. • PheRRB8 localise to the nucleus and cytoplasm, and have transactivation activity in yeast. • PheRRB8 may play a key role in phytohormone signal transduction and environmental stress response. • Overexpression of PheRRB8 weakened Arabidopsis thaliana tolerance to salt stress. [ABSTRACT FROM AUTHOR]

Stable culm variants are valuable and important material for the study of culm development in bamboo plants. However, to date, there are few reports on the mechanism of variation of these bamboo variants. Phyllostachys nidularia f. farcta (Shidu bamboo) is a bamboo variant with stable phenotypes such as a dwarf culm with a thickened wall. In this study, we systematically investigated the cytological characteristics and underlying mechanism of morphological variation in culms of this variant using anatomical, mathematical statistical, physiological, and genomic methods. The anatomical observation and statistical results showed that the lateral increase of ground tissue in the inner layer of culm wall and the enlargement of vascular bundles are the anatomical essence of the wall thickening of Shidu bamboo; the limited elongation of fiber cells and the decrease in the number of parenchyma cells longitudinally are probably the main causes of the shortening of its internodes. A number of genes involved in the gibberellin synthesis pathway and in the synthesis of cell wall components are differentially expressed between the variant and its prototype, Ph. nidularia , and may play an important role in determining the phenotype of internode shortening in Shidu bamboo. The decrease in gibberellin content and the content of the major chemical components of the cell wall of Shidu bamboo confirmed the results of the above transcriptome. In addition, the variation in culm morphology in Shidu bamboo had little effect on the volume of the culm wall of individual internodes, suggesting that the decrease in the total number of internodes and the decrease in dry matter content (lignin, cellulose, etc.) may be the main factor for the sharp decline in culm biomass of Shidu bamboo. [ABSTRACT FROM AUTHOR]

One of the excellent characteristics of bamboo is the deformation stability. However, the reasons for the good bending stability of bamboo have not been well studied. In this study, we examined the pathways that controls bending deformation in bamboo. A hand-bent phyllostachys iridescens member was chosen to examine continuous density distribution, microfibril angle (MFA) and modulus of elasticity (MOE) along radial direction using SilviScan analysis. Our results show that in bent bamboo, MFA is lower in tension sample and higher in compression sample than neutral sample. There is a strong linear positive correlation between density and MOE, while negative linear correlation between MOE and MFA and no obvious linear correlation between MFA and density. Increased bending was influential in primarily changing the MOE, while also altering the density distribution and MFA. Our results demonstrate variation in density, MOE and MFA distribution along radial direction of tension, neutral and compression samples, which play an important role in maintaining the bending characteristics of bamboo. [ABSTRACT FROM AUTHOR]

Background: The DoG (Delay of Germination1) family plays a key regulatory role in seed dormancy and germination. However, to date, there is no complete genomic overview of the DoG gene family of any economically valuable crop, including moso bamboo (Phyllostachys edulis), and no studies have been conducted to characterize its expression profile. To identify the DoG gene members of moso bamboo (PeDoG) and to investigate their family structural features and tissue expression profile characteristics, a study was conducted. Based on the whole genome and differential transcriptome data, in this investigation, we have scrutinized the physicochemical properties, gene structure, cis-acting elements, phylogenetic relationships, conserved structural (CS) domains, CS motifs and expression patterns of the PeDoG1 family of moso bamboo. Results: The DoG family genes of moso bamboo were found distributed across 16 chromosomal scaffolds with 24 members. All members were found to carry DoG1 structural domains, while 23 members additionally possessed basic leucine zipper (bZIP) structural domains. We could divide the PeDoG genes into three subfamilies based on phylogenetic relationships. Covariance analysis revealed that tandem duplication was the main driver of amplification of the PeDoG genes. The upstream promoter of these genes containing several cis-acting elements indicates a plausible role in abiotic stress and hormone induction. Gene expression pattern according to transcriptome data revealed participation of the PeDoG genes in tissue and organ development. Analysis using Short Time-series Expression Miner (STEM) tool revealed that the PeDoG gene family is also associated with rapid early shoot growth. Gene ontology (GO) and KEGG analyses showed a dual role of the PeDoG genes. We found that PeDoGs has a possible role as bZIP transcription factors by regulating Polar like1 (PL1) gene expression, and thereby playing a disease response role in moso bamboo. Quantitative gene expression of the PeDoG genes revealed that they were abundantly expressed in roots and leaves, and could be induced in response to gibberellin (GA). Conclusion: In this study, we found that the PeDoG genes are involved in a wide range of activities such as growth and development, stress response and transcription. This forms the first report of PeDoG genes and their potential roles in moso bamboo. [ABSTRACT FROM AUTHOR]

Background: Orphan gene play an important role in the environmental stresses of many species and their identification is a critical step to understand biological functions. Moso bamboo has high ecological, economic and cultural value. Studies have shown that the growth of moso bamboo is influenced by various stresses. Several traditional methods are time-consuming and inefficient. Hence, the development of efficient and high-accuracy computational methods for predicting orphan genes is of great significance. Results: In this paper, we propose a novel deep learning model (CNN + Transformer) for identifying orphan genes in moso bamboo. It uses a convolutional neural network in combination with a transformer neural network to capture k-mer amino acids and features between k-mer amino acids in protein sequences. The experimental results show that the average balance accuracy value of CNN + Transformer on moso bamboo dataset can reach 0.875, and the average Matthews Correlation Coefficient (MCC) value can reach 0.471. For the same testing set, the Balance Accuracy (BA), Geometric Mean (GM), Bookmaker Informedness (BM), and MCC values of the recurrent neural network, long short-term memory, gated recurrent unit, and transformer models are all lower than those of CNN + Transformer, which indicated that the model has the extensive ability for OG identification in moso bamboo. Conclusions: CNN + Transformer model is feasible and obtains the credible predictive results. It may also provide valuable references for other related research. As our knowledge, this is the first model to adopt the deep learning techniques for identifying orphan genes in plants. [ABSTRACT FROM AUTHOR]

Auxin plays a crucial regulatory role in higher plants, but systematic studies on the location of auxin local biosynthesis are rare in bamboo and other graminaceous plants. We studied moso bamboo (Phyllostachys edulis), which can grow up to 1 m/day and serves as a reference species for bamboo and other fast-growing species. We selected young tissues such as root tips, shoot tips, young culm sheaths, sheath blades, and internode divisions for local auxin biosynthesis site analysis. IAA immunofluorescence localization revealed that auxin was similarly distributed in different stages of 50-cm and 300-cm bamboo shoots. Shoot tips had the highest auxin content, and it may be the main site of auxin biosynthesis in the early stage of rapid growth. A total of 22 key genes in the YUCCA family for auxin biosynthesis were identified by genome-wide identification, and these had obvious tissue-specific and spatio-temporal expression patterns. In situ hybridization analysis revealed that the localization of YUCCA genes was highly consistent with the distribution of auxin. Six major auxin synthesis genes, PheYUC3-1 , PheYUC6-1 , Phe YUC6-3 , PheYUC9-1 , PheYUC9-2 , and PheYUC7-3 , were obtained that may have regulatory roles in auxin accumulation during moso bamboo growth. Culm sheaths were found to serve as the main local sites of auxin biosynthesis and the auxin required for internode elongation may be achieved mainly by auxin transport. [ABSTRACT FROM AUTHOR]

Bletilla striata is a terrestrial orchid with high ornamental and medicinal values that is widely interplanted in bamboo forests. However, little is known about the effects of bamboo forest type and density on the growth of B. striata and its symbiotic relationship with root endophytic fungi. In this study, the growth state of B. striata, the community composition and diversity of its root endophytic fungal, and the fungal nutritional function were investigated in Phyllostachys edulis, P. iridescens and P. glauca forests with three densities. We found that the type and density of the bamboo forest had significant effects on the growth of B. striata, with the biomass, leaf width, root quantity and width being the highest in the low-density of the P. edulis forest. The community composition and abundance of root endophytic fungi in B. striata varied among different bamboo forests and densities, with P. edulis and P. iridescens forests dominated by Basidiomycota and Serendipita, while P. glauca prevailed by Ascomycota and Dactylonectria. The trophic modes of root endophytic fungi were also affected by forest types and densities. The abundance of symbiotroph fungi was the highest in P. edulis and P. iridescens forests and greatly varied with density gradient, and saprotrophic fungi comprised the highest proportion in the Ph. glauca forest. These results provide basic data for further research and the configuration between bamboo species and terrestrial orchids. [ABSTRACT FROM AUTHOR]

Accurate estimations of leaf biomass are required to quantify the amount of material and energy exchanged between vegetation and the atmosphere, to enhance the primary productivity of forest stands, and to assess the contributions of vegetation towards the mitigation of global climate change. The leaf biomass of Moso bamboo (Phyllostachys edulis (Carrière) J. Houz) changes dramatically during the year owing to changes in the leaves and the growth of new shoots. Furthermore, the relationship between the leaf biomass of Moso bamboo under cutting the top of the culm and the diameter at breast height (D) and culm height is decoupling, which increases the difficulty of estimating leaf biomass. Consequently, an effective method to accurately estimate the leaf biomass of Moso bamboo under cutting the top of the culm is required. In this study, leaf biomass and other factors (age, D, culm height, crown length, and crown width) were measured for 54 bamboo samples collected from December 2019 to December 2020. Models for predicting the leaf biomass of the Moso bamboo were established using multiple linear regression with two strategies, and their accuracies were evaluated using leave-one-out cross-validation. The results showed that crown length, crown width, and age were highly correlated with leaf biomass, and these were important factors when making estimations. Variation in monthly averaged leaf biomass is significant, with a decreasing trend from January to May and an increasing trend from June to December in off-years. The leaf biomass model that utilized data from the three leaf change periods had a better fit and accuracy, with R2 values of 0.583–0.848 and prediction errors between 8.59% and 24.19%. The model that utilized data for all months had a worse fit and accuracy, with an R2 value of 0.228 and prediction error of 46.79%. The results of this study provide reference data and technical support to help clarify the dynamic changes in Moso bamboo leaf biomass, and therefore, aid in the development of accurate simulations. [ABSTRACT FROM AUTHOR]

Background: Hypoxia stress is thought to be one of the major abiotic stresses that inhibits the growth and development of higher plants. Phyllostachys pracecox is sensitive to oxygen and suffers soil hypoxia during cultivation; however, the corresponding solutions to mitigate this stress are still limited in practice. In this study, Spermidine (Spd) was tested for regulating the growth of P. praecox seedlings under the hypoxia stress with flooding. Results: A batch experiment was carried out in seedlings treated with 1 mM and 2 mM Spd under flooding for eight days. Application of 1 mM and 2 mM Spd could alleviate plant growth inhibition and reduce oxidative damage from hypoxia stress. Exogenous Spd significantly (P < 0.05) increased proline, soluble protein content, catalase (CAT), superoxide dismutase (SOD), and S-adenosylmethionine decarboxylase (SAMDC) activity, enhanced abscisic acid (ABA) and indole-3-acetic acid (IAA) content, and reduced ethylene emission, hydrogen peroxide (H2O2), superoxide radical (O2·−) production rate, ACC oxidase (ACO) and ACC synthase (ACS) to protect membranes from lipid peroxidation under flooding. Moreover, exogenous Spd up-regulated the expression of auxin-related genes auxin responsive factor1 (ARF1), auxin1 protein (AUX1), auxin2 protein (AUX2), auxin3 protein (AUX3) and auxin4 protein (AUX4), and down-regulated the expression of ethylene-related ACO and ACS genes during flooding. Conclusion: The results indicated that exogenous Spd altered hormone concentrations and the expression of hormone-related genes, thereby protecting the bamboo growth under flooding. Our data suggest that Spd can be used to reduce hypoxia-induced cell damage and improve the adaptability of P. praecox to flooding stress. [ABSTRACT FROM AUTHOR]

The TALE gene family is a subfamily of the homeobox gene family and has been implicated in regulating plant secondary growth. However, reports about the evolutionary history and function of the TALE gene family in bamboo are limited. Here, the homeobox gene families of moso bamboo Olyra latifolia and Bonia amplexicaulis were identified and compared. Many duplication events and obvious expansions were found in the TALE family of woody bamboo. PhTALEs were found to have high syntenies with TALE genes in rice. Through gene co-expression analysis and quantitative real-time PCR analysis, the candidate PhTALEs were thought to be involved in regulating secondary cell wall development of moso bamboo during the fast-growing stage. Among these candidate PhTALEs, orthologs of OsKNAT7, OSH15, and SH5 in moso bamboo may regulate xylan synthesis by regulating the expression of IRX-like genes. These results suggested that PhTALEs may participate in the secondary cell wall deposition in internodes during the fast-growing stage of moso bamboo. The expansion of the TALE gene family may be implicated in the increased lignification of woody bamboo when divergent from herbaceous bamboos. [ABSTRACT FROM AUTHOR]

Phyllostachys edulis (P. edulis) bamboo is the most widely distributed and used bamboo species, and it is an ideal building material. With the in-depth implementation of the sustainable development strategy, modern bamboo structures have broad application prospects in green buildings. In order to promote the efficient utilization of bamboo resources and facilitate the design and application of bamboo structures, the bending strength test and classification of P. edulis bamboo were carried out, the factors affecting the reliability were analyzed, and the design values of the bending strength of P. edulis bamboo were proposed based on the reliability analysis. The research results show that dividing P. edulis bamboo into three levels (grade I, grade II, and grade III) can achieve efficient use of P. edulis bamboo resources; 75% fitting data points and normal distribution were used to analyze the reliability of the bending strength of P. edulis bamboo. The analysis of factors affecting reliability makes the calculation of strength design values more reliable. The reliability increases with the increase of the load ratio and the partial factor for resistance. Under the same load ratio and reliability, the partial factor for resistance of the combination of constant load and snow load is the largest, and the partial factor for resistance of the combination of constant load and office building load is the smallest. Under the same load combination and reliability, the partial factor for resistance decreases as the load ratio increases. Under the same load ratio and load combination, the partial factor for resistance of grade III is the largest, and grade I is the smallest. The bending strength design values of grade I, grade II, and grade III are 29.54 MPa, 29.62 MPa, and 30.63 MPa, respectively. This paper innovatively proposed the design values of bending strength of P. edulis bamboo based on classification. The P. edulis bamboo grading method established in this paper and the bending strength design values of P. edulis bamboo proposed can provide references for the design and engineering application of bamboo structures. [ABSTRACT FROM AUTHOR]

The secondary cell wall of bamboo parenchyma cells is microfibril-based. However, understanding of the microfibril orientation of secondary cell walls in bamboo parenchyma cells is lacking. This study characterized the microfibril orientation of the sub-layers of the secondary cell wall in the parenchyma cells by field-emission environmental scanning electron microscopy and the microfibril angle of the ground parenchyma cell wall with X-ray diffraction. The microfibril orientation of tight-loose alternating layers of the secondary cell wall was in the opposite direction along the longitudinal axis. Near the parenchyma cells' pit aperture, the microfibril orientation generally bypassed the pits and continued in a flow-like pattern. The mean microfibril angle of ground parenchyma cells was 63.3°. The average microfibril angle of adjacent sub-layers of the secondary cell wall was 60° and − 65° in ground parenchyma cells, and 54° and − 52° in vascular parenchyma cells. A structure model of microfibril orientation of parenchyma cell wall in moso bamboo was firstly constructed. The study provides insight into the anatomical structure of the parenchyma cell wall in the bamboo plant. Moreover, it provides a structural basis for further analysis of the mechanical properties of parenchyma cells. [ABSTRACT FROM AUTHOR]

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Little is known on how karst plants adapt to highly heterogeneous habitats via adjusting leaf anatomical structures. Phyllostachys glauca McClure is a dominant species that grow across different microhabitats in the limestone mountains of Jiangxi Province, China. We investigated the leaf anatomical structures, plant biomass, soil water content, soil total nitrogen (TN), and soil total phosphorus (TP) from three habitats characterized by different rock exposure, including high rock exposure (HRE), medium rock exposure (MRE) and low rock exposure (LRE), and aimed to discern the relationships between the leaf anatomical plasticity and edaphic factors. The leaves of P. glauca in different habitats showed significant anatomical plasticity in two aspects. First, the leaves adjusted cuticle thickness, papillae length, bulliform cell size and mesophyll thickness to lower water loss and then adapt to the water-deficient habitats (HRE). Second, the leaves enlarged vessels and vascular bundles (first-order and second-order parallel veins) to improve water and nutrient transportation and then enhance plant growth in nitrogen-rich habitats (HRE). Soil water and soil nutrients purely explained the total variation of leaf anatomical traits by 21.7% and 15.7%, respectively, and had a shared proportion of 15.8%. Our results indicated that the leaf anatomical variations in different habitats were associated with both soil water and soil nutrients. Moreover, we found that leaf anatomical structures were more affected by TN than TP. The present study advanced the current understanding of the strategies employed by karst plants to cope with highly heterogeneous habitats via leaf anatomical plasticity. [ABSTRACT FROM AUTHOR]

Light is one of the most important environmental factors affecting growth and geographic distribution of forestry plants. Moso bamboo is the largest temperate bamboo on earth and an important non-woody forestry species that serves not only important functions in the economy of rural areas but also carbon sequestration in the world. Due to its decades-long reproductive timing, the germplasm of moso bamboo cannot be readily improved by conventional breeding methods, arguing for a greater need to study the gene function and regulatory mechanisms of this species. We systematically studied the photoregulatory mechanisms of the moso bamboo (Phyllostachys edulis) cryptochrome 1, PheCRY1. Our results show that, similar to its Arabidopsis counterpart, the bamboo PheCRY1s are functionally restricted to the blue light inhibition of cell elongation without an apparent activity in promoting floral initiation. We demonstrate that PheCRY1s undergo light-dependent oligomerization that is inhibited by PheBIC1s, and light-dependent phosphorylation that is catalyzed by PhePPKs. We hypothesize that light-induced phosphorylation of PheCRY1s facilitate their degradation, which control availability of the PheCRY1 proteins and photosensitivity of bamboo plants. Our results demonstrate the evolutionary conservation of not only the function but also photoregulatory mechanism of PheCRY1 in this monocot forestry species. [ABSTRACT FROM AUTHOR]

A novel chromone analogue, phyllomakin A (1), and a new flavonolignan, (-)-quiquelignan C (2), along with 18 phenolic and 2 triterpenoids, were isolated from the leaves of Phyllostachys makinoi Hayata. The structures of 1–22 were elucidated by an application of various spectroscopic analyses (1D & 2D NMR and MS) and compared with reported data. A biological evaluation showed that compound 3 had very potent anti-NO production activity (IC50 = 4.80 µM), while compounds 2, 6, 11, and 15 showed moderate inhibitory effects (IC50 = 10.19, 13.26, 13.56, and 10.96 µM, respectively) without affecting cell viability at 20 μM. [ABSTRACT FROM AUTHOR]

In order to enrich the data on genome sizes of Polygonatum species, flow cytometry was used for ploidy detection and estimation of genome sizes of four Polygonatum species recorded in the Chinese Pharmacopoeia, including P. kingianum, P. sibiricum, P. cyrtonema, and P. odoratum from different habitats. The results show that Phyllostachys pubescens can be used as a suitable reference standard for the estimation of genome sizes of Polygonatum species. Regarding the four diploid Polygonatum species, the present study found that the genome size of P. odoratum（13 829-14 083 Mb） is similar to that of P. kingianum（13 780 Mb); the genome size of P. sibiricum（12 792-13 516 Mb） is slightly smaller than that of P. odoratum and P. kingianum; and the genome size of P. cyrtonema（9 311 Mb） is the smallest. The genome size of triploid P. cyrtonema is 11 032-11 267 Mb, which is 1.2 times larger than that of diploid P. cyrtonema. The genome size of tetraploid P. kingianum is 12 088-12 411 Mb, which is 89% of the size of diploid P. kingianum. The results append the data on the genome sizes of Polygonatum species, which will provide a reference for a follow-up study on genomics, species classification, and population evolution. [ABSTRACT FROM AUTHOR]

In this study, the influence of interplanting Dictyophora indusiata under a Phyllostachys edulis forest on bamboo growth and soil nutrient changes was analyzed. Traditionally managed bamboo forests were used as a control（CK), D. indusiata was interplanted under a P. edulis forest, and three substrates were designed for D. indusiata cultivation（A.100% rice husk; B. 50% rice husk+50% bamboo shavings; C. 100% bamboo shavings). The results showed that the number of shoots, grown bamboos, and diameter at breast height（DBH), of A, B, and C were significantly higher than those of CK, in which the shoots increased by 16.63%, 12.50%, and 37.50%, number of grown bamboos increased by 22.70%, 22.70%, and 31.77%, and DBH increased by 11.93%, 25.55%, and 12.38%, respectively. Compared with the control, the soil pH value of the interplanted plot increased and soil acidification reduced. Soil organic matter, alkali-hydrolyzable nitrogen, available phosphorus, and available potassium increased significantly compared with the control; however, there was no significant difference in total nitrogen, total phosphorus, and total potassium. It was found that the soil quality index of the interplanting plots was higher than that of CK. Therefore, interplanting D. indusiata under P. edulis forests significantly promotes the number of shoots and bamboos, growth of new bamboos, availability of soil nutrients and comprehensive soil quality, and has a positive effect on soil nutrients and the growth of Moso bamboo forests. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs) are a class of endogenous noncoding RNAs formed by 3′-5′ ligation during splicing. They play an important role in the regulation of transcription and miRNA in eukaryotes. Drought is one of the detrimental abiotic stresses that limit plant growth and productivity. How circRNAs influence the response to drought stress in moso bamboo (Phyllostachys edulis) remains elusive. In this study, we investigate the expression pattern of circRNAs in moso bamboo at 6 h, 12 h, 24 h and 48 h after drought treatment by deep sequencing and bioinformatics analysis and identify 4931 circRNAs, 52 of which are differentially expressed (DEcircRNAs) in drought-treated and untreated moso bamboo. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of the host genes that generate the DEcircRNAs indcate that these DEcircRNAs are predicted to be involved in biochemical processes in response to drought, such as ubiquitin-mediated proteolysis, calcium-dependent protein kinase phosphorylation, amino acid biosynthesis and plant hormone signal transduction including abscisic acid. In addition, some circRNAs are shown to act as sponges for 291 miRNAs. Taken together, our results characterize the transcriptome profiles of circRNAs in drought responses and provide new insights into resistance breeding of moso bamboo. [ABSTRACT FROM AUTHOR]

Moso bamboo (Phyllostachys edulis) is the most important monopodial bamboo species worldwide. Without a genetic transformation system, it is difficult to verify the functions of genes controlling important traits and conduct molecular breeding in moso bamboo. Here, we established a plant regeneration system from immature embryos. Calli were induced on MS medium added 4–6 mg⋅L–1 2,4-dichlorophenoxyacetic acid (2,4-D) with high efficiency (>60%). A plant growth regulator combination of 0.5 mg⋅L–1 1-naphthylacetic acid (NAA), 2.0 mg⋅L–1 6-benzylaminopurine (BAP), and 3.0 mg⋅L–1 zeatin (ZT) was suitable for shoot differentiation, and the shoot induction frequency was increased to 43% after 0.5 mg⋅L–1 abscisic acid (ABA) pretreatment. An effective antibiotic screening concentration was determined by hygromycin sensitivity test. We further optimized the Agrobacterium concentration and added vacuum infiltration for infection, which improves the transient expression efficiency. A genetic transformation system was established for the first time in moso bamboo, with the transformation efficiency of approximately 5%. To optimize genome editing, two endogenous U3 small nuclear RNA (snRNA) promoters were isolated and used to drive small guide RNA (sgRNA) expression. The results showed that the PeU3.1 promoter exhibited higher efficiency, and it was used for subsequent genome editing. Finally, homozygous pds1pds2 mutants were obtained by an efficient CRISPR/Cas9 genome-editing system. These technical systems will be conducive to gene functional validation and accelerate the molecular breeding process of moso bamboo. [ABSTRACT FROM AUTHOR]

Plant fine-root decomposition is an important pathway for the reentry of nutrients into the soil. Studies have mainly focused on the loss of fine-root mass and the release characteristics of major elements, including, C, N, and P, but there are few reports on trace elements. In this study, in situ decomposition experiments were conducted to study the dynamic characteristics of mass loss and residual rates of 10 mineral elements in two diameter classes (<2 mm and 2–5 mm) of moso bamboo in the process of fine-root decomposition. The results of the year-long experiment reported herein showed that: (1) fine roots with diameters of less than 2 mm decomposed faster than those with diameters of 2–5 mm; (2) C, N, P, K, Ca, and Mg were released, whereas Fe, Mn, Zn, and Cu were enriched or changed little; (3) decomposition time and root diameter had significant effects on the remaining percentages of C, N, K, Ca, Mg, Mn, Zn, and Cu, and there were interactions among the elements (P < 0.05). The remaining percentages of P and Fe were only affected by decomposition time. This is the first comprehensive report on the variation in 10 elements during the fine-root decomposition of moso bamboo. The study expands our understanding of the release of mineral nutrients during fine-root decomposition, laying a solid theoretical foundation for further research on fine-root decomposition and plant–soil nutrient cycling. [ABSTRACT FROM AUTHOR]

Bamboo, being an ornamental plant, has myriad aesthetic and economic significance. Particularly, Phyllostachys violascens cv. Viridisulcata contains an internode color phenotype in variation in green and yellow color between the sulcus and culm, respectively. This color variation is unique, but the underlying regulatory mechanism is still unknown. In this study, we used metabolomic and transcriptomic strategies to reveal the underlying mechanism of variation in internode color. A total of 81 metabolites were identified, and among those, prunin as a flavanone and rhoifolin as a flavone were discovered at a high level in the culm. We also found 424 differentially expressed genes and investigated three genes (PvGL , PvUF7GT , and PvC12RT1) that might be involved in prunin or rhoifolin biosynthesis. Their validation by qRT-PCR confirmed high transcript levels in the culm. The results revealed that PvGL , PvUF7GT , and PvC12RT1 might promote the accumulation of prunin and rhoifolin which were responsible for the variation in internode color of P. violascens. Our study also provides a glimpse into phenotypic coloration and is also a valuable resource for future studies. [ABSTRACT FROM AUTHOR]

hyllostachys edulis bamboo is one of the most valuable bamboo species in the world. It has the following advantages: high strength, light weight, and green, renewable character. In addition, it has a broad application prospect under the background of developing green buildings all over the world. The moisture content and density are the key factors affecting the mechanical properties of bamboos. However, there is no two-variable model of the mechanical properties with respect to the moisture content and density of P. edulis bamboo. In this paper, analysis of the compression parallel to the grain, bending, tensile parallel to the grain, and shear parallel to the grain of P. edulis bamboo were performed. The relationship between the mechanical properties and the moisture content and density was fitted by a two-variable model. The results show that the two-variable model has good fitting effect. As such, the two-variable model can be used to predict the mechanical properties of P. edulis bamboo according to its moisture content and density. [ABSTRACT FROM AUTHOR]

Summary: Ground parenchyma cells play a crucial role in the growth and the mechanical properties of bamboo plants. Investigation of the morphology of ground parenchyma cells is essential for understanding the physiological functions and mechanical properties of these cells. This study aimed to characterize the anatomical structure of bamboo ground parenchyma cells and provide a qualitative and quantitative basis for the more effective utilization of bamboo. To do this, the morphology of ground parenchyma cells in Moso bamboo (Phyllostachys edulis) was studied using light microscopy and field-emission environmental scanning electron microscopy. Results show that various geometric shapes of ground parenchyma cells were observed, including nearly circular, square, long, oval, and irregular shapes. Cell walls of both long and short parenchyma cells exhibited primary wall thickening and secondary wall thickening, resulting in a primary pit field and simple pits. Most long cells were strip-shaped (L / W = 2.52), while most short cells were short and wide (L / W = 0.59). The proportion of long cells was 11 times greater than that of short cells. Most long cells were filled with starch grains, and some short cells also occasionally had starch grains. These findings allowed the first construction of the three-dimensional structure of parenchyma cells. [ABSTRACT FROM AUTHOR]

Phyllostachys nigra var. henonis (Poales: Poaceae) is a tall, temperate bamboo species that has a long monocarpic life history with a flowering interval of around 120 years that is often conspicuously synchronized across a wide geographical area. Interestingly, observations of the last major flowering event, which was about a century ago, suggested that mature seeds were rarely produced as a consequence. As this bamboo has recently started flowering across Japan after a century of silence, we seek to understand its reproductive strategy by quantifying the following four issues: (1) flowering patterns within stands, (2) the presence or absence of mature seeds, (3) resource allocations to reproductive parts, and (4) asexual regrowth capacity after mass flowering. We conducted field surveys at five flowering bamboo stands in Japan. At each, many spikelets were found, but neither mature seeds nor seedlings. During the mass flowering, large amounts of resources were allocated to reproductive parts, accounting for 57% of the aboveground nitrogen pool and 63% of the aboveground phosphorus pool. These results indicate that the accumulated resources were used for flowers, but not for seed production, and thus apparently in vain. While most of the flowering ramets appeared to die, dwarf ramets (mostly less than 1 m in height) typically regenerated from the remaining belowground rhizomes and seem to be critical for maintaining the bamboo stands. This apparently inefficient sexual reproductive strategy still exists (without local extinction) perhaps due to the vigorous clonal growth system and to human‐assisted distribution. [ABSTRACT FROM AUTHOR]