Lignification in developing culms of bamboo Sinobambusa tootsik

Abstract

Bamboos are among the largest woody grasses and grow very rapidly. Although lignin is a crucial factor for the utilization of bamboo biomass, the lignification mechanism of bamboo shoots is poorly understood. We studied lignification in the bamboo Sinobambusa tootsik during culm development. Elongation growth began in May and ended in late-June, when the lignin content was approximately half that in mature culms. Thioacidolysis analysis indicated that p-hydroxyphenyl units in lignin formed even at late stages of lignification. The syringyl/ guaiacyl ratio varied during culm development. Various lignin precursors were detected in developing culms by liquid chromatography-mass spectrometry. The ferulic acid content decreased from May to June, indicating that ferulic acid was utilized in early stages of cell wall formation. Monolignol glucosides were detected at early stages of lignification, whereas the contents of monolignols, coniferaldehyde, sinapaldehyde, p-coumaric acid, and ferulic acid peaked at later stages of lignification. Therefore, lignin precursors may be supplied differentially during the lignification process. In August, the rate of lignification decreased, although the contents of various lignin precursors peaked, implying that the rate-limiting step in the cessation of lignification in bamboo is transport or polymerization of lignin precursors, rather than their biosynthesis.

Proton Gradient-Dependent Transport of p-Glucocoumaryl Alcohol in Differentiating Xylem of Woody Plants

“…p -Hydroxyphenyl lignin is a minor component of cell walls and its physiological role is unclear; however, it is assumed to perform critical roles in the compound middle lamella, such as aiding in cell rigidity. The H ratio pattern observed in differentiating xylem of poplar was different to that observed during bamboo shoot development 25 , which implies that the role of H lignin may differ among plant species.…”

Age-dependent and radial sectional differences in the dynamic viscoelastic properties of bamboo culms and their possible relationship with the lignin structures

“…1). Huang et al [24] revealed the Moso bamboo density of the internodes parts and the nodes parts reduce from the external surface to the internal surface of the culm wall in the radial direction by anatomical analysis and computed tomography scanning quantifications. They also indicated that the different proportions of the vascular bundle tissues and the parenchyma ground tissues dominate the density variation of the Moso bamboo in the radial direction.…”

“…While the yield of thioacidolysis and peak temperature tan δ value increased until 3.5 Y. A recent study suggested that the formation rate of β-O-4 linkages differs during development of bamboo [24]. The proportion of β-O-4-linked G or S units with free phenolic groups was decreased in mature lignin compared with immature lignin, which indicates that the frequency of internal units increased with maturation [39].…”

“…This indicates that lignin is deposited constantly over several years. Tsuyama et al [24] reported that the formation rate of β-O-4 linkages and S/G ratio may differ during development of bamboo. In our previous study, it was found that the age-dependent changes in the microfibril angles of cell walls could be important factors related to the mechanical properties of bamboo [2].…”

Application of Bamboo Plants in Nine Aspects

“…The identification of distribution and content of lignin is important to determine the critical period of bamboo elongation and biomass. The results of one study indicated that when the content of lignin in the culm reaches half of the mature culms at the end of June, growth elongation became complete [ 37 ]. However, the most important reason involved in the explosive growth of bamboo is related to nonstructural carbohydrates (NSCs).…”