Genome-wide identification and evolution of WNK kinases in Bambusoideae and transcriptional profiling during abiotic stress in Phyllostachys edulis

With-no-lysine (WNK) kinases play vital roles in abiotic stress response, circadian rhythms, and regulation of flowering time in rice, Arabidopsis, and Glycine max. However, there are no previous reports of WNKs in the Bambusoideae, although genome sequences are available for diploid, tetraploid, and hexaploid bamboo species. In the present study, we identified 41 WNK genes in five bamboo species and analysed gene evolution, phylogenetic relationship, physical and chemical properties, cis-elements, and conserved motifs. We predicted the structure of PeWNK proteins of moso bamboo and determined the exposed, buried, structural and functional amino acids. Real-time qPCR analysis revealed that PeWNK5, PeWNK7, PeWNK8, and PeWNK11 genes are involved in circadian rhythms. Analysis of gene expression of different organs at different developmental stages revealed that PeWNK genes are tissue-specific. Analysis of various abiotic stress transcriptome data (drought, salt, SA, and ABA) revealed significant gene expression levels in all PeWNKs except PeWNK11. In particular, PeWNK8 and PeWNK9 were significantly down- and up-regulated, respectively, after abiotic stress treatment. A co-expression network of PeWNK genes also showed that PeWNK2, PeWNK4, PeWNK7, and PeWNK8 were co-expressed with transcriptional regulators related to abiotic stress. In conclusion, our study identified the PeWNKs of moso bamboo involved in circadian rhythms and abiotic stress response. In addition, this study serves as a guide for future functional genomic studies of the WNK genes of the Bambusoideae.

Flexural Behavior of Six Species of Italian Bamboo

The good mechanical performance of bamboo, coupled with its sustainability, has boosted the idea to use it as a structural material. In some areas of the world it is regularly used in constructions but there are still countries in which there is a lack of knowledge of the mechanical properties of the locally-grown bamboo, which limits the spread of this material. Bamboo is optimized to resist to flexural actions with its peculiar micro structure along the thickness in which the amount of fibers intensifies towards the outer layer and the inner part is composed mostly of parenchyma. The flexural strength depends on the amount of fibers, whereas the flexural ductility is correlated to the parenchyma content. This study focuses on the flexural strength and ductility of six different species of untreated bamboo grown in Italy. A four-point bending test was carried out on bamboo strips in two different loading configurations relating to its microstructure. Deformation data are acquired from two strain gauges in the upper and lower part of the bamboo beam. Difference in shape and size of Italian bamboo species compared to the ones traditionally used results in added complexity when performing the tests. Such difficulties and the found solutions are also described in this work. The main goal is to reveal the flexural behavior of Italian bamboo as a functionally graded material and to expand the knowledge of European bamboo species toward its use as a structural material not only as culm but also as laminated material.

Composition, Community Structure and Vertical Distribution of Epiphytic Ferns on Bamboo Species In Bogor Botanic Gardens, Indonesia

Ecological study of epiphytic ferns growing on bamboo species in Bogor Botanic Gardens, a man-made ecosystem located in a wet lowland area was carried out. The 350 phorophytes of 35 bamboo clumps belonging to 9 species and 3 genera were observed. Each culm was divided into intervals of 1 m from ground level to a height of 3 m. A total of 1984 individuals belonging to 12 species, nine genera, and six families of epiphytic ferns were recorded, with the highest species richness in Polypodiaceae (7 spp.). Dendocalamus giganteus Munro was the best host for epiphytic ferns (9 spp.). Two dominant species, Asplenium nidus L. and Davallia denticulata (Burm.f.) Mett. ex Kuhn with the same frequency value (97.14%), and relative species abundance of 31.49 individuals per clump and 14.94 individuals per clump, showed the highest Importance Value Index (IVI) of 83.19 and 54.00%, respectively. The first one-meter level of bamboo culms hosted all the species. Pyrrosia piloselloides (L.) Price was the only species that grew until the highest intervals of height with a decreasing frequency from the bottom. Bangladesh J. Bot. 50(4): 1095-1107, 2021 (December)

Study of Homogeneous Chipboard Manufacturing u sing Betung Bamboo (Dendrocalamus Asper) Mixed with Polyethylene Addictive

Bamboo is an evergreen plant native to Asia and America that grows at every altitude, even in unideal climate conditions. Betung bamboo or its scientific name Dendrocalamus Asper is one of the bamboo species that are easily found in peninsular Malaysia. This study examined the characteristics of Betung bamboo and its potential to manufacture chipboard. Several tests were conducted, namely modulus of elastic (MOE), modulus of rupture (MOR), thickness swelling (TS), and water absorption (WA) to evaluate the potential of Betung bamboo as the primary material in the manufacture of chipboard mixed with polyethylene as additive are the parameters considered. This study found that the composition of 70% bamboo and 30% polyethylene was produced optimum chipboard which met BS EN standards (British and European Standard). It was also found that the MOE and MOR values of the resulting chipboard exceeded the medium density board standards. For WA and TS values, the chipboard achieved the standard requirements. Thus, this study concludes that chipboard made of Betung bamboo with the addition of polyethylene is suitable to be applied for internal and external doors, and internal paneling for any commercial or domestic building and furniture.

Ethno-bamboo Approaches to the Pala’wan in the Mangrove Area of Palawan Island, the Philippines

Bamboo is an important resource in Southeast Asia, which is a hotspot of bamboo species diversity globally, and has historically contributed to livelihoods in various environments. Subsistence livelihoods are still widely found in Southeast Asia, especially in isolated villages, and various kinds of plant resources, including bamboo, support local livelihoods. Understanding the relationship between human society and plants is important to understand the historical process of expansion and adaptation of human society in Southeast Asia; however, despite its importance, information on bamboo utilization remains limited. A field survey was conducted in a village located in the mangrove area of Palawan Island, the Philippines. The residents were the Pala’wan. Data was obtained through participatory observation and interview survey to at least 30 villagers. In the village, 10 bamboo species, both wild and cultivated, were utilized for various purposes, with a large and specific demand for bamboo of cultivated species. These species are medium to large in size, and some are distributed widely both inmainland and insular Southeast Asia. These bamboo species are considered to have been brought by Southeast Asian people along with other useful plants and have adapted to the new environment. To understand the long-term relationship between Asian people and plants, it is necessary to consider bamboo, and multidisciplinary integration of knowledge, which can be called as the “ethno-bamboo approach,” can uncover new aspects of this relationship.

Nitric Oxide Ameliorates Plant Metal Toxicity by Increasing Antioxidant Capacity and Reducing Pb and Cd Translocation

Recently, nitric oxide (NO) has been reported to increase plant resistance to heavy metal stress. In this regard, an in vitro tissue culture experiment was conducted to evaluate the role of the NO donor sodium nitroprusside (SNP) in the alleviation of heavy metal toxicity in a bamboo species (Arundinaria pygmaea) under lead (Pb) and cadmium (Cd) toxicity. The treatment included 200 µmol of heavy metals (Pb and Cd) alone and in combination with 200 µM SNP: NO donor, 0.1% Hb, bovine hemoglobin (NO scavenger), and 50 µM L-NAME, N(G)-nitro-L-arginine methyl ester (NO synthase inhibitor) in four replications in comparison to controls. The results demonstrated that the addition of L-NAME and Hb as an NO synthase inhibitor and NO scavenger significantly increased oxidative stress and injured the cell membrane of the bamboo species. The addition of sodium nitroprusside (SNP) for NO synthesis increased antioxidant activity, protein content, photosynthetic properties, plant biomass, and plant growth under heavy metal (Pb and Cd) toxicity. It was concluded that NO can increase plant tolerance for metal toxicity with some key mechanisms, such as increasing antioxidant activities, limiting metal translocation from roots to shoots, and diminishing metal accumulation in the roots, shoots, and stems of bamboo species under heavy metal toxicity (Pb and Cd).

An Allometric Model Based Approach For Estimating Biomass In Seven Indian Bamboo Species In Western Himalayan Foothills, India

The rapid growth rate, high biomass production, and annual harvesting, makes bamboo as suitable species for commercial production. Allometric equations for many broadleaf and conifer tree species are available. However, knowledge on biomass production and allometric equations of bamboos are limited. This study aims at developing species specific allometric models for predicting biomass and synthetic height values as a proxy variable for seven bamboo species in Himalayan foothills. Two power form based allometric models were used to predict above ground and culm biomass using Diameter at breast height (D) alone and D in combination with culm height (H) as independent variable. This study also extended to establishing H-D allometric model that can be used to generate synthetic H values as proxy to missing H. In the seven bamboo species studied, among three major biomass component (culm, branch and foliage), culm is the most important component with highest share (69.56 to 78.71%).Distribution of percentage (%) share of culm, branch and foliage to above ground fresh weight varies significantly between different bamboo species. D. hamiltonii has highest productivity for above ground biomass components. Ratio of dry to fresh weight of seven bamboo species was estimated for culm, branch, foliage and above ground biomass to convert fresh weight to dry weight.

PHYSICAL, CHEMICAL AND MORPHOLOGICAL CHARACTERISTICS OF BAMBOO SPECIES GUADUA TRINII AND GUADUA ANGUSTIFOLIA AND THEIR POTENTIAL TO PRODUCE HIGH-VALUE PRODUCTS

High-value products can be obtained from non-traditional lignocellulosic resources, such as bamboo, taking full advantage of these materials through efficient, low-cost and low-pollution fractionation processes. This work aims to analyze the physical, chemical, and morphological differences between two bamboo species as a rapidly growing resource of great regional interest – Guadua trinii and Guadua angustifolia. Both samples were characterized in terms of basic density, morphological characteristics, and chemical composition. This work shows that G. trinii has a significantly denser woody structure, with a uniform density at the sampled culm height. The internal structure consists of a parenchyma matrix and vascular bundles composed of parenchyma cells and fiber bundles. G. angustifolia has significantly longer fibers. Chemical characterization showed differences between the carbohydrate and lignin contents. The results of this work are critical to know the potential of both bamboo species as a source of high-value products in the bamboo biorefinery framework.

Cell Wall Pore Structures of Bamboo as Relation to Species and Tissue Types

Efficient convention of bamboo biomass into biofuel and biomaterials, as well as chemical treatment are both highly related to the porosity of cell wall. The present work characterizes the micropore and mesopore structure in cell walls of six different bamboo species and tissue types using CO2 and N2 adsorption. Two plantation wood species were also tested for comparison. Bamboo species normally showed lower cell wall porosity (2.64%-3.75%) than wood species (3.98%-5.06%), indicating a more compact structure for bamboo than wood. A distinct species dependence of cell wall pore structures and porosity was also observed. Furthermore, the cell wall pore structure and porosity are shown to be tissue-specific, as the parenchyma cells exhibit higher pore volume and porosity compared to bamboo fibers. The obtained results give new explanations on the known facts that both bamboo and bamboo fibers exhibit higher biomass recalcitrance as compared to wood and bamboo parenchyma cells, constructing the base of pretreatment optimization and subsequent processing for bamboo-derived biofuels and biomaterials.