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The primary thickening growth of Moso (Phyllostachys edulis) underground shoots largely determines the culm circumference. However, its developmental mechanisms remain largely unknown. Using an integrated anatomy, mathematics and genomics approach, we systematically studied cellular and molecular mechanisms underlying the growth of Moso underground shoots. We discovered that the growth displayed a spiral pattern and pith played an important role in promoting the primary thickening process of Moso underground shoots and driving the evolution of culms with different sizes among different bamboo species. Different with model plants, the shoot apical meristem (SAM) of Moso is composed of six layers of cells. Comparative transcriptome analysis identified a large number of genes related to the vascular tissue formation that were significantly upregulated in a thick wall variant with narrow pith cavity, mildly spiral growth, and flat and enlarged SAM, including those related to plant hormones and those involved in cell wall development. These results provide a systematic perspective on the primary thickening growth of Moso underground shoots, and support a plausible mechanism resulting in the narrow pith cavity, weak spiral growth but increased vascular bundle of the thick wall Moso.

In this study, the potential of bagasse pith (the waste of sugar and paper industry) was investigated for bio-xylitol production for the first time. Xylose-rich hydrolysate was prepared using 8% dilute sulfuric acid, at 120 °C for 90 min. Then, the acid-hydrolyzed solution was detoxified by individual overliming (OL), active carbon (AC), and their combination (OL+AC). The amounts of reducing sugars and inhibitors (furfural and hydroxyl methyl furfural) were measured after acid pre-treatment and detoxification process. Thereafter, xylitol was produced from detoxified hydrolysate by Rhodotorula mucilaginosa yeast. Results showed that after acid hydrolysis, the sugar yield was 20%. Detoxification by overliming and active carbon methods increased the reducing sugar content up to 65% and 36% and decreased the concentration of inhibitors to >90% and 16%, respectively. Also, combined detoxification caused an increase in the reducing sugar content (>73%) and a complete removal of inhibitors. The highest productivity of xylitol (0.366 g/g) by yeast was attained after the addition of 100 g/l non-detoxified xylose-rich hydrolysate into fermentation broth after 96 h, while the xylitol productivity enhanced to 0.496 g/g after adding the similar amount of xylose-rich hydrolysate detoxified by combined method (OL+AC2.5%).

Stem and pith necrosis symptoms on tomato and midrib rot symptoms on lettuce were observed in West and East Azarbayjan of Iran. Infected organs of the plants were collected and bacterial strains were isolated on NA medium. Biochemical and physiological properties such as LOPAT test, fluorescent pigment production and utilization of carbon source, demonstrated that the strains were Pseudomonas cichorii. All strains were pathogenic on tomato and lettuce plants. To assess genetic diversity among the strains, BOX and ERIC-PCR analyses were employed. Clustering of ERIC and BOX-PCR results with UPGMA and Jaccard’s similarity coefficients showed that strains were clustered into two main groups at a similarity level of 52%. Strains of groups 1 and 2 isolated from lettuce and tomato, respectively. The gyrB, rpoD and 16S rRNA nucleotide sequences showed high similarity and the sequence similarity between the Iranian strains and P. cichorii reference strain were 98.9, 98.7 and 99.5%, indicating a close phylogenetic relationship between the strains. According to the past references and researches in Iran, this is the first report of isolation and identification of Pseudomonas cichorii, the causative agent of tomato pith necrosis and lettuce midirib rot in North West of Iran.

The hybrid Bohemian knotweed [Polygonum ×bohemicum (J. Chrtek & Chrtková) Zika & Jacobson [cuspidatum × sachalinense]; syn.: Reynoutria ×bohemica Chrtek & Chrtková] is part of the worldwide problematic rhizomatous invasive plants that impact (semi-)natural and agricultural systems. In this context, precise knowledge about the morpho-anatomy and resprouting capacity of the underground organs is key information for developing efficient eradication measures. In the present study, we aimed at (1) clarifying existing differences in the morpho-anatomical characteristics of rhizomes and roots, (2) developing an easy-to-apply field identification method for the underground organs, and (3) identifying the main morpho-anatomical features enhancing the rhizomes' resprouting ability. For this purpose, we collected the underground organs of two wild populations of P. ×bohemicum in Canton Ticino (southern Switzerland) and analyzed the morpho-anatomical differences between rhizomes and roots, using high-resolution microscope images and microtome sections. Collected material was then used for a resprouting capacity test after assessing rhizome characteristics such as weight, total diameter, pith diameter, pith brightness, and pith color. In contrast to roots, rhizomes are characterized by pith tissue in the center and display nodes with peripheral dormant buds that enable them to resprout. Resprouting ability of rhizomes was high (87.1% on average) and depended on the ontogenetic developmental stage of the organs (peak values of 97% for young and clearer-colored organs, 50% for old and dark ones). In conclusion, the smooth pith tissue of rhizomes represents a key discriminating feature between rhizomes and roots, whereas relating existing nodes to the corresponding rhizome pith color allows assessment of the resprouting potential of a knotweed population.

Dye wastewater currently damages both human health and aquatic ecosystem, so to reduce its negative effects and promote sustainable development, this study optimizes cellulose extraction process from coconut coir pith via employing response surface methodology combined with Design Expert software (version 11.0.1.0, Copyright©2017, Stat-Ese Inc., USA). The recovered cellulose after alkalizing and decolorizing process is applied to assess its adsorption capability of methylene blue from water. Methylene blue adsorption capacity is evaluated based on operating factors: pH, contact time, methylene blue initial concentration and cellulose mass. The success of cellulose extraction process is established by Fourier-transform infrared spectroscopy, X-Ray Diffraction and Thermogravimetric analysis. The recovered cellulose particles have a high crystallinity index of 46.39% and high purity of 35.63% with an average diameter of 344 μm with a specific surface area of 3.303 m 2 .g −1 , a porous structure with a pore diameter of 34.952Å and pH pzc of 6.14. Under optimal adsorption conditions, methylene blue adsorption efficiency of 99.22% is achieved, and the process is favorable, reversible, and monolayer adsorption. The adsorption in this work is in good agreement with pseudo-second-order kinetic model and physical adsorption is the main adsorption mechanism. Importantly, the recovered cellulose has a significantly high adsorption capacity of 145.81 mg.g −1 after seven continuous using times. These findings propose that cellulose can recover from coconut coir pith by-product and holds a highly potential on dye removal from aqueous solution. Graphical abstract

The coir industry in India’s southern coastal regions, especially in the state of Kerala, is becoming increasingly concerned about the environmental impact of the accumulation and incremental increase of coir pith each year. The objective of this study was to assess the effect of pretreatment on the anaerobic digestion of coir pith. The characterization study of coir pith shows high organic content, which can be anaerobically digested to produce biogas. But, the high lignin content (30.91%) makes the process slow. To overcome this, a biological pretreatment method was tried using two microbial cultures belonging to fungal genera known to be lignin decomposers, viz., Trichoderma and Pleurotus. By using Trichoderma, lignin content was reduced by 3.7%, and the maximum gas production was obtained in a shorter time (19 days) in comparison with the sample without any pretreatment (24 days). When Pleurotus was used for lignin degradation, the lignin content was reduced by 6.78%, and the maximum gas production was obtained in a much shorter time period (14 days) in comparison with the former two methods. The gas produced comprises 74 ppm of methane, which has fuel value. The sludge after digestion was tested, which indicated a marginal increase in NPK value and hence can be used as fertilizer. The results of the study appear to be quite promising in the transition towards green energy by providing scope for the process of biomethanation, with the conclusion that further research can transform coir pith into a good renewable energy resource.

In rice, internode elongation is a critical aspect of plant development and agricultural productivity. Previous morphological and histochemical studies using [ 3 H]thymidine have visualized the cell division zone (intercalary meristem) in internodes. However, it has remained unclear how the intercalary meristem forms during stem development. In addition, while a pith cavity forms in the central part of the rice stem, the spatiotemporal relationship between pith cavity formation and intercalary meristem development is not well understood. Therefore, we performed histological analysis of intercalary meristem and pith cavity development using C9285, a deepwater rice variety that shows internode elongation from the vegetative growth stage. We classified the developmental stages of the stem into four stages based on the analysis of pith cavity formation using Trypan blue, Calcein-AM, and MitoRed staining, and visualized dividing cells using the Click-iT EdU imaging assay. In Stage 1, no pith cavity was formed. Vertical cell rows were observed between above the axillary bud attachment and the upper node, suggesting anticlinal divisions that lead to internode formation in the early stage of stem development. In Stage 2, the first pith cavity formed in the pith of the foot, which is the region of axillary bud attachment. Compared to cell division in the internode, that in the foot was significantly activated resulting in slight elongation from Stage 1 to Stage 2. In Stage 3, cell division in the foot ceased, while active cell division at the base of the internode led to significant vertical elongation. The second pith cavity formed due to cell death in the pith of the internode. In Stage 4, the two pith cavities connected to form a single large pith cavity. Although the intercalary meristem maintained cell division activity, the number of cell divisions decreased. Based on these results, we propose a model for stem development that involves two phases of elongation regulation: primary elongation involving slight elongation in the foot, and secondary elongation involving significant internode elongation due to the activation of cell division and cell elongation in the intercalary meristem. This is the first study to anatomically elucidate the spatiotemporal relationship between intercalary meristem development and pith cavity formation in rice stem development. It provides new insights for future research on rice stem development and studies of other grass species.

Phosphorous, in the form of phosphate, is a key element in the nutrition of all living beings. In nature, it is present in the form of phosphate salts, organophosphates, and phosphonates. Bacteria transport inorganic phosphate by the high affinity phosphate transport system PstSCAB, and the low affinity PitH transporters. The PstSCAB system consists of four components. PstS is the phosphate binding protein and discriminates between arsenate and phosphate. In the Streptomyces species, the PstS protein, attached to the outer side of the cell membrane, is glycosylated and released as a soluble protein that lacks its phosphate binding ability. Transport of phosphate by the PstSCAB system is drastically regulated by the inorganic phosphate concentration and mediated by binding of phosphorylated PhoP to the promoter of the PstSCAB operon. In Mycobacterium smegmatis, an additional high affinity transport system, PhnCDE, is also under PhoP regulation. Additionally, Streptomyces have a duplicated low affinity phosphate transport system encoded by the pitH1–pitH2 genes. In this system phosphate is transported as a metal-phosphate complex in simport with protons. Expression of pitH2, but not that of pitH1 in Streptomyces coelicolor, is regulated by PhoP. Interestingly, in many Streptomyces species, three gene clusters pitH1–pstSCAB–ppk (for a polyphosphate kinase), are linked in a supercluster formed by nine genes related to phosphate metabolism. Glycerol-3-phosphate may be transported by the actinobacteria Corynebacterium glutamicum that contains a ugp gene cluster for glycerol-3-P uptake, but the ugp cluster is not present in Streptomyces genomes. Sugar phosphates and nucleotides are used as phosphate source by the Streptomyces species, but there is no evidence of the uhp gene involved in the transport of sugar phosphates. Sugar phosphates and nucleotides are dephosphorylated by extracellular phosphatases and nucleotidases. An isolated uhpT gene for a hexose phosphate antiporter is present in several pathogenic corynebacteria, such as Corynebacterium diphtheriae, but not in non-pathogenic ones. Phosphonates are molecules that contains phosphate linked covalently to a carbon atom through a very stable C–P bond. Their utilization requires the phnCDE genes for phosphonates/phosphate transport and genes for degradation, including those for the subunits of the C–P lyase. Strains of the Arthrobacter and Streptomyces genera were reported to degrade simple phosphonates, but bioinformatic analysis reveals that whole sets of genes for putative phosphonate degradation are present only in three Arthrobacter species and a few Streptomyces species. Genes encoding the C–P lyase subunits occur in several Streptomyces species associated with plant roots or with mangroves, but not in the laboratory model Streptomyces species; however, the phnCDE genes that encode phosphonates/phosphate transport systems are frequent in Streptomyces species, suggesting that these genes, in the absence of C–P lyase genes, might be used as surrogate phosphate transporters. In summary, Streptomyces and related actinobacteria seem to be less versatile in phosphate transport systems than Enterobacteria.

Abstract Pseudomonas spp. isolates were collected from tomato plants showing symptoms of pith necrosis during the 2017 and 2018 seasons in the Salto Department, northwest Uruguay. According to physiological, biochemical tests and multilocus phylogenetic analysis (gyrB, rpoD, and rpoB), 25 were characterized as P. mediterranea, five as P. viridiflava, three as P. corrugata, and one as P. marginalis. All of them produced necrotic lesions and pith hollowing in re-inoculated tomato plants. Some P. mediterranea isolates (UYT92018, UYT122018, UYT192018, UYT222018, and UYT372018 from season 2018) did not develop a hypersensitive response (HR) in tobacco like the other P. mediterranea, P. corrugata, P. viridiflava, and P. marginalis isolates. According to our knowledge, this is the first documented report of P. viridiflava and P. marginalis causing tomato pith necrosis in Uruguay. As well as the presence of several Pseudomonas spp. causing tomato pith necrosis in the Salto area P. mediterranea was confirmed to be the most prevalent.

Summary Pith cavity formation is critical for bamboo to overcome the bending force during its fast growth; however, the underlying molecular mechanisms remain largely unknown. Multiple approaches, including anatomical dissection, mathematical modelling and transcriptome profiling, were employed in this study to investigate the biology of pith cavity formation in bamboo Pseudosasa japonica. We found that the corruption of pith tissue occurred sequentially and asymmetrically from the top‐centre of the internode down to the bottom, which might be caused by the combined effects of asymmetrical radial and axial tensile forces during shoot‐wall cell elongation and spiral growth of bamboo internodes. Programmed cell death (PCD) in pitch manifested by TUNEL positive nuclei, DNA cleavage and degraded organelles, and potentially regulated by ethylene and calcium signalling pathway, ROS burst, cell wall modification, proteolysis and nutrient recycle genes, might be responsible for pith tissue corruption of Ps. japonica. Although similar physiological changes and transcriptome profiles were found in different bamboo species, different formation rates of pith cavity were observed, which might be caused by different pith cells across the internode that were negatively correlated with the culm diameter. These findings provided a systematical view on the formation of bamboo pith cavity and revealed that PCD plays an important role in the bamboo pith cavity formation.