Activation of Cryptic Secondary Metabolite Biosynthesis in Bamboo Suspension Cells by a Histone Deacetylase Inhibitor.

Plants have evolved a diverse array of secondary metabolite biosynthetic pathways. Undifferentiated plant cells, however, tend to biosynthesize secondary metabolites to a lesser extent and sometimes not at all. This phenomenon in cultured cells is associated with the transcriptional suppression of biosynthetic genes due to epigenetic alterations, such as low histone acetylation levels and/or high DNA methylation levels. Here, using cultured cells of bamboo (Bambusa multiplex; Bm) as a model system, we investigated the effect of histone deacetylase (HDAC) inhibitors on the activation of cryptic secondary metabolite biosynthesis. The Bm suspension cells cultured in the presence of an HDAC inhibitor, suberoyl bis-hydroxamic acid (SBHA), exhibited strong biosynthesis of some compounds that are inherently present at very low levels in Bm cells. Two major compounds induced by SBHA were isolated and were identified as 3-O-p-coumaroylquinic acid (1) and 3-O-feruloylquinic acid (2). Their productivities depended on the type of basal culture medium, initial cell density, and culture period, as well as the SBHA concentration. The biosynthesis of these two compounds was also induced by another HDAC inhibitor, trichostatin A. These results demonstrate the usefulness of HDAC inhibitors to activate cryptic secondary metabolite biosynthesis in cultured plant cells.

Identification and characterization of two bamboo (Phyllostachys praecox) AP1/SQUA-like MADS-box genes during floral transition.

Bamboo (Bambusoideae) is by far the largest member of the grass family Poaceae, which is vital to the economy of many countries in the tropics and subtropics. However, the mechanism of flowering of bamboo (Phyllostachys praecox) is still unknown. In this study, we isolated two novel genes from P. praecox and evaluated their functional characteristics. The sequence and phylogenetic analysis indicated that these two genes, named PpMADS1 and PpMADS2, belong to FUL3 and FUL1 clade of Poaceae AP1/SQUA-like genes, respectively. The PpMADS2 possesses a truncated C terminus lacking the highly conserved paleoAP1 motif. It was further confirmed that the truncated C-terminal region was produced by natural sequence deletion in exons, but not by alternative splicing. Ectopic expression of PpMADS1 and PpMADS2 significantly promoted early flowering through upregulation of AP1 in Arabidopsis. Yeast two-hybrid experiments demonstrated that AP1 protein can interact with PpMADS1 but not PpMADS2, suggesting that these two genes may act differently in signaling early flowering of bamboo plants. RT-qPCR and in situ hybridization analysis revealed distinct expression patterns of these two genes in vegetative and reproductive tissues of bamboo. Taken together, our results suggest that both PpMADS1 and PpMADS2 are involved in floral transition, and PpMADS2 might play more important roles than PpMADS1 in floral development of Phyllostachys praecox.

Water effects on the deformation and fracture behaviors of the multi-scaled cellular fibrous bamboo.

Natural bamboo with different water weight contents (0%, 6% and 22%) had distinguishingly different mechanical properties, where samples with water contents of 22% had tensile strength and elongations increased by ∼30% and ∼200% than the dry (0%), respectively. The deformation and fracture process was synchronously recorded and analyzed with the aid of the acoustic emission (AE), during which there were three kinds of real time fracture behaviors recognized: matrix (multi-walled parenchyma cells) failure, interfacial (fiber/fiber or fiber/parenchyma cell walls) dissociations and fiber breakage. More interfacial dissociations and higher fracture energy were detected as more water was added, since water molecules can make great differences on the bamboo's inner micro-structures and the mechanical properties. During the fracture process of the wet bamboo detected by AE, matrix failure and interfacial dissociations contributed most of the elongation, and the strength were mainly depended on the fiber breakage and interfacial dissociations. The discovered structural toughening mechanisms within the multi-scaled structures were microfiber bridging, multi-walled fiber pull-out, micro warts buckling and crack deflection. The micro-structural toughening effects were strengthened by the cellulose-hemicellulose-lignin complexes and a certain content of water molecules within the multi-scaled fibrous cellular structures, which are collaboratively working and ensuring the high mechanical performance of the natural bamboo. STATEMENT OF SIGNIFICANCE: The mechanical behaviors during the whole fracture process of bamboo were investigated by acoustic emission (AE). During the fracture process there were three kinds of fracture behaviors recognized by AE: matrix (parenchyma cells) failure, interfacial (fiber/fiber or fiber/parenchyma cell walls) dissociations and fiber breakage. The mechanical performance was greatly influenced by water contents (0%, 6% and 22%). Wet bamboos had higher fracture energy than the dry ones. There was more interfacial dissociation behaviors detected as more water was absorbed within the multi-scaled structures. The micro structural toughening mechanisms were strengthened by the macromolecular complexes and water molecules, which are working together and ensuring the excellent mechanical properties of the natural bamboo.

Efficacy of bioconversion of paper mill bamboo sludge and lime waste by composting and vermiconversion technologies.

Paper mill bamboo sludge (PMBS) and Paper mill lime waste (PMLW) are extensively produced as solid wastes in paper mills. Untreated PMBS and PMLW contain substantial amount of heavy metals (Zn, Pb, Ni, Cd, Cr) in soluble forms. Efficiency of vermiconversion and aerobic composting with these wastes is reported here. Adopted bioconversion systems enhanced the availability of some essential nutrients (N, P, K and Zn) in various combinations of cow dung (CD) with PMBS and PMLW. Colonization of nitrogen fixing bacteria and phosphate solubilizing bacteria considerably intensified under the vermiconversion system. Moreover, significant metal detoxification occurred due to vermiconversion. Various combinations of bioconverted PMBS and PMLW were applied to tissue cultured bamboo (Bambusa tulda) and chilli (Capsicum annum). Accelerated nutrient uptake coupled with improved soil quality resulted in significant production of chilli. Furthermore, vermiconverted PMBS+CD (1:1) and PMLW+CD (1:3) confirmed as potential enriching substrate for tissue cultured bamboo.

Identification of programmed cell death related genes in bamboo.

The event of bamboo flowering and subsequent death of bamboo cells, a rare phenomenon is an interesting model to study gene expression/function in the context of the programmed cell death (PCD) in plant. To identify genes involved in autolytic cell death in bamboo (Bambusa arundinacea/Bambusa bambos Voss), a suppressive subtractive cDNA hybridization (SSH) was performed between cDNA isolated from control (healthy), as driver and test internodal tissue (45days after setting of seeds), as tester. In-silico data revealed that 82% of total ESTs (231) were non-significant (unidentified proteins) while remaining ESTs were classified as protein with known/predicted function/s. Among these, net distribution and differential expression patterns of 11 important B. arundinacea PCD specific ESTs were studied using RNA slot-blot, qRT-PCR and semi-quantitative RT. In-situ localization of mRNA-transcripts for selected bamboo PCD-specific ESTs namely V2Ba48 (Aldehyde dehydrogenase 2) and V2Ba19 (Glycogen phosphorylase) were detected using digoxigenin-labeled corresponding anti-sense RNA probes employing Confocal Laser Scanning Microscope (CLSM). Differential expression-kinetics of the aforementioned genes were confirmed during the progress of PCD after setting of seeds. Global appearance of V2Ba48, V2Ba19, V2Ba95 (Ubiquitin thioesterase) and V2Ba89 (Nebulin isoform 2) genes were identified in monocot (Oryza sativa) and dicots (Arabidopsis thaliana and Nicotiana tabacum). This is the first report on systematic analysis of genes involved in death of bamboo cells that may provide critical information regarding key metabolic/regulatory genes involved in plant PCD.

Avaliação farmacognostica qualitativa das folhas do vegetal Bambusa textilis / Qualitative pharmacognostic evaluation of leaves of Bambusa textilis

Introdução: Os bambus pertencem à família Graminae, subfamília Bambusoidae, representados por cerca de 1250 espécies no mundo. Originalmente empregados na construção civil e alimentação, atualmente são alvo de investigações relacionadas às suas propriedades terapêuticas em neoplasias. As principais espécies utilizadas para fins terapêuticos baseado no conhecimento popular são: Phyllostachys nigra; Bambusa breiflora; Bambusa tuldoides e a Bambusa textilis. A literatura sobre a ação terapêutica das espécies de bambu é escassa, porém estudos recentes relatam um promissor efeito no tratamento de neoplasias e outras doenças crônicas. Objetivo: O presente estudo teve como principal objetivo avaliar, qualitativamente a composição fitoquímica de extrato vegetal obtido a partir das folhas da espécie de bambu Bambusa textilis, comparando esta composição entre folhas de vegetais com 18 e 24 meses de idade. Metodologia: Após a coleta de folhas do vegetal com 18 ou 24 meses, as mesmas foram identificadas e submetidas à secagem e moagem. Para análise qualitativa de seus componentes foram empregados os métodos de avaliação macroscópica (mucilagens), método do Benjoim (resinas), reação de Shinoda (flavonóides), reação com solução de gelatina (taninos), fervura e formação de espuma (saponinas) e empregos dos reativos de Wagner, Bertrand, Dragendorff, Mayer, ácido pícrico e ácido tânico (alcalóides) (BIAVATTI; LEITE, 2007). Resultados: nas folhas mais jovens foram encontrados resultados positivos para alcalóides, flavonóides, resinas e saponinas. Nas folhas do vegetal com 24 meses foram encontrados apenas alcalóides flavonóides e resinas.

Introduction: Bamboos belong to the family Graminae, Bambusoidae subfamily, represented by about 1,250 species worldwide. Originally employed in construction and power, are currently the subject of investigations related to its therapeutic properties in neoplasms.The main species used for therapeutic purposes based on popular knowledge are: Phyllostachys nigra; Bambusa breiflora; tuldoides Bambusa textilis and Bambusa. The literature on the therapeutic action of bamboo species is scarce, but recent studies report a promising effect in the treatment of cancer and other chronic diseases. Objective: This study aimed to evaluate qualitatively the phytochemical composition of plant extract obtained from the leaves of the bamboo species Bambusa textilis, comparing this composition from vegetable leaves with 18 and 24 months of age. Methodology: After collecting plant leaves with 18 or 24 months, they were identified and submitted to drying and milling. For qualitative analysis of its components were employed methods of macroscopic evaluation (mucilage), method of benzoin (resin), reaction Shinoda (flavonoids), reaction with gelatin solution (tannins), boiling and foaming (saponins) and jobs of reactive Wagner, Bertrand, Dragendorff, Mayer, picric acid and tannic acid (alkaloids) (Biavatti; MILK, 2007). Results: in the youngest leaves were found positive for alkaloids, flavonoids, resins and saponins. In the leaves of the plant with 24 months were found only alkaloids flavonoids and resins.

Immunohistochemical localization of hemicelluloses and pectins varies during tissue development in the bamboo culm.

The distribution of hemicelluloses and pectins in bamboo internodes was studied immunocytochemistrically at various stages of development. The ultra-structures of bamboo cell walls have been reported previously at various stages. The internodes were identically classified into three developmental phases: primary wall stage (phase I), unlignified secondary wall stage (phase II) and lignified wall stage (phase III), using the same bamboo culm. (1-->3, 1-->4)-Beta-glucans were distributed in nearly all tissues in an actively elongating stage. Limited amounts of beta-glucans were deposited in primary walls and the middle lamellae, but were limited to the phloem in secondary walls. This suggests that the function of beta-glucans might be different in phloem vis-à-vis other tissues. Highly-substituted xylans were located in nearly all tissues of early phase I, but had disappeared in all tissues immediately prior to lignification. In contrast, low-branched xylan epitopes were present only in the protoxylem in phase I, but were present in all tissues immediately prior to lignification in phase II. In phase III, the epitopes were densely localized in lignified walls, suggesting that the substitution of xylans is closely related to maturation. Methyl-esterified (but not unesterified) pectins were present in all tissues of early phase I. Just before and after lignification, both types of pectins were concentrated in the phloem and protoxylem. Xyloglucans were largely distributed in the phloem and in lignified tissues, suggesting that they might be closely correlated with maturation. This represents the first account of the distribution of hemicelluloses and pectins at the tissue and ultrastructural level in bamboo internodes at various stages of development.