Part Of Internode Research Articles

Comparative Study on Vascular Bundle Morphological Characteristics of Parts of Branches, Culms, and Rhizomes of Oligostachyum sulcatum

This study presents a comprehensive analysis of the vascular bundle morphology, tangential and radial diameters, and distribution frequency of different parts of Oligostachyum sulcatum, elucidating their structural and functional significance. Electron microscopy images revealed distinct vascular bundle characteristics in the different parts, including the vascular bundles in both parts of the rhizomes, the middle parts of the internodes, and the middle and inner parts of the branches, which were semi-open. The vascular bundles in the outer parts of both internodes and branches were semi-differentiated and undifferentiated. The vascular bundles in the inner parts of internodes were open. Statistical analysis showed significant variations in tangential and radial diameters among these parts, reflecting their diverse mechanical and physiological functions. The internodes exhibited the largest tangential and radial diameters, suggesting a critical role in mechanical support. In contrast, the branches had the smallest diameter, indicating that vascular bundle differentiation is influenced by growth conditions. The vascular bundle frequency was the highest in branches and the lowest in inside-sticks. This study provides theoretical references for the adaptive strategies and growth regulation mechanisms of O. sulcatum.

Anatomical study on the developmental process of the swollen internodes of Phryma (Phrymaceae, eudicots).

We discovered that the internodal swellings of Phryma (eudicots) stems were same as the internodal pulvini of Poaceae (monocots) from the viewpoints of internal structures and functions. The stems of eudicots are usually rod-shaped and are composed of nodes, attached by leaves, and internodes. The internodes of some species, belonging to the clade 'asterids' and its sister clade 'Caryophyllales' of eudicots, have swellings, which have negative tropism, at the basal or apical part of each internode. To know the internal features of the swollen internodes, we performed outer morphological and anatomical studies on the swollen internodes of Phryma, eudicots, one of the genera having swollen internodes, from the winter bud stage to the flowering stage. The results revealed the following: (i) the swollen regions of the internodes were composed of less lignified tissues (e.g., endodermis without Casparian strips, and xylem having less lignified xylem fibers); (ii) the internodal less lignified parts were supported by collenchyma; (iii) the endodermis includes amyloplasts, having accumulated starch granules, which would function as statoliths for negative gravitropism. Consequently, we determined that the swollen parts of the Phryma internodes are same as the internodal pulvini of Poaceae of monocots from the viewpoints of internal structures and functions.

The cost of myrmecophytism: insights from allometry of stem secondary growth

Plant defence traits against herbivores incur production costs that are usually difficult to measure. However, estimating these costs is a prerequisite for characterizing the plant defence strategy as a whole. Myrmecophytes are plants that provide symbiotic ants with specialized nesting cavities, called domatia, in exchange for protection against herbivores. In the particular case of stem domatia, production of extra wood seems to be the only associated cost, making this indirect defence trait a particularly suitable model for estimating the cost of defence. Measurements were made of growth pattern and cumulative production cost of domatia over secondary growth in the myrmecophyte Leonardoxa africana subsp. africana, whose internodes display both a solid basal segment and a hollow distal part (the domatium), thus allowing paired comparison of investment in wood. Previous studies showed that 'overconstruction' of the hollow part of internodes during primary growth is needed for mechanical support. In this study, it is shown that the relationship between the woody cross-sectional area of the solid and hollow parts of internodes is negatively allometric at the beginning of secondary growth and nearly isometric later on. Thus, in hollow stems, the first phase of slow secondary growth compensates for the 'overconstruction' of the ring of wood during primary growth. Moreover, the cumulative production cost of a domatium (estimated as the additional volume of wood required for a hollow stem compared with a solid one) is very high at the beginning of secondary growth and then quickly tends to zero. Making domatia incurs high costs early in ontogeny, costs that are then amortized later in development of stems and of individual plants. Characterizing ontogenetic variation of the net cost of this peculiar defence mechanism will help us build more accurate theoretical models of resource allocation in myrmecophytes.

Induction of anthocyanins accumulation by methyl jasmonate in shoots of Crassula multicava Lam.

In Crassula multicava Lam. anthocyanins are formed naturally mostly in the stem near nodes and only traces in other parts of internodes. Methyl jasmonate (JA-Me) applied in lanolin paste at concentrations of 0.05, 0.1, 0.5 and 1.0% on the middle part of internodes greatly stimulated anthocyanins accumulation in the internodes and in the nodes of <i>Crassula multicava</i>. The stimulatory effect was higher in younger tissues of the <i>Crassula multicava</i> stem than in older ones, and depends on the used concentration of JA-Me. The possible role of jasmonates on anthocyanins formation in <i>Crassula multicava</i> is discussed.

Developmental Control of Lignification in Stems of Lowland Switchgrass Variety Alamo and the Effects on Saccharification Efficiency

The switchgrass variety Alamo has been chosen for genome sequencing, genetic breeding, and genetic engineering by the US Department of Energy Joint Genome Institute (JGI) and the US Department of Energy BioEnergy Science Center. Lignin has been considered as a major obstacle for cellulosic biofuel production from switchgrass biomass. The purpose of this study was to provide baseline information on cell wall development in different parts of developing internodes of tillers of switchgrass cultivar Alamo and evaluate the effect of cell wall properties on biomass saccharification. Cell wall structure, soluble and wall-bound phenolics, and lignin content were analyzed from the top, middle, and bottom parts of internodes at different developmental stages using ultraviolet autofluorescence microscopy, histological staining methods, and high-performance liquid chromatography (HPLC). The examination of different parts of the developing internodes revealed differences in the stem structure during development, in the levels of free and well-bound phenolic compounds and lignin content, and in lignin pathway-related gene expression, indicating that the monolignol biosynthetic pathway in switchgrass is under complex spatial and temporal control. Our data clearly show that there was a strong negative correlation between overall lignin content and biomass saccharification efficiency. The ester-linked p-CA/FA ratio showed a positive correlation with lignin content and a negative correlation with sugar release. Our data provide baseline information to facilitate genetic modification of switchgrass recalcitrance traits for biofuel production.

Changes in Cell Wall-Bound Phenolic Acids in the Internodes of Submerged Floating Rice

Submergence induces rapid elongation of internodes in floating rice (Oryza sativa L.). We examined the distributions of p-coumaric, ferulic and 5-5-coupled diferulic acids ester-linked to cell walls along the axis of highest internodes of submerged and air-grown floating rice stem segments. The amounts of ferulic and 5-5-diferulic acids per cell wall weight were lowest around the intercalary meristem, and increased as the distance from the meristematic zone increased toward the upper part of the internode in both air-grown and submerged stem segments. The ratio of 5-5-diferulic acid to ferulic acid also increased toward the upper, old parts of internodes in both air-grown and submerged stem segments. These observations suggest that the feruloylation of cell wall polysaccharides and the formation of diferulic acids contribute to the cessation of internodal cell elongation and that the formation of diferulic acids in cell walls is controlled by the coupling reaction in addition to the feruloylation. The amounts of p-coumaric acid per unit length and per cell-wall weight were markedly low in the newly elongated region of submerged internodes, and closely correlated with cell-wall dry mass in both air-grown and submerged internodes, suggesting that the deposition of p-coumaric acid in cell walls is related to the formation of secondary cell walls in floating rice internodes.

Reed canary grass observations of effects on crop stand and fibre quality caused by infestation of Epicalamus phalaridis

A severe infestation of the gall midge Epicalamus phalaridis (Diptera: Cecidomyiidae)occurred in a field of reed canary grass, Phalaris arundinacea in northern Sweden. The midge species has potential to become a serious pest on Phalaris grown for bioenergy or fibre production. Larvae of the midge feed beneath leaf sheaths and the crop lodges in late summer. Details are given on the biology of the midge. In the infested field, population densities of the midge were very high during three consecutive years. The crop was weakened and the occurrence of weeds increased. The dry matter yields declined markedly and were after three years of midge-attack about 50% of the average yield in the preceding years. The yield dropped comparatively more when the crop was harvested in the spring as opposed to harvest in late autumn and more at a nitrogen fertilisation at 100 kg compared to 200 kg N ha–1 per year. The effect of midge attack on fibre quality was studied. The fibre properties of midge-infested parts of internodes were poor, but as midge-damaged parts are brittle, they could probably be sorted out in a fractionation process. Undamaged parts of infested internodes had the same fibre properties as those from an uninfested crop.;

Changes in cell wall polysaccharides in the internodes of submerged floating rice

In excised stem segments of floating rice (Oryza sativa L.), as well as in intact plants, submergence greatly stimulates the elongation of internodes. The differences in the composition of cell wall polysaccharides along the highest internodes of submerged and air-grown stem segments were examined. The newly elongated parts of internodes that had been submerged for two days contained considerably less cellulosic and noncellulosic polysaccharides than air-grown internodes, an indication that the cell walls of the newly elongated parts of submerged internodes are extremely thin. In the young parts of both air-grown and submerged internodes, the relative amounts of noncellulosic polysaccharides were equal to those of α-cellulose, whereas the relative amounts of α-cellulose were higher than those of noncellulosic polysaccharides in the upper, old parts. In the cell-elongation zones of both air-grown and submerged internodes, glucose was predominant among the noncellulosic neutral sugars of cell wall. The relative amount of glucose in noncellulosic neutral sugars decreased toward the upper, old parts of internodes, whereas that of xylose increased.

A computer simulation of conduction in demyelinated nerve fibres.

1. The theoretical effects of demyelination on conduction of a propagated impulse have been examined in a computer simulated myelinated nerve fibre. Demyelination was simulated by increasing the capacitance and conductance of the myelin sheath of individual internodes or parts of internodes.2. Internodal conduction time increased as myelin thickness was decreased. The increase in internodal conduction time became more precipitous as the myelin became thinner. Propagation continued past a single demyelinated internode until myelin thickness was uniformly reduced to less than 2.7% of normal myelin thickness.3. Paranodal demyelination was more effective in slowing impulse conduction than was uniform demyelination of an entire internode with an equivalent rise in overall internodal capacitance and conductance.4. The effects on conduction of demyelination of two adjacent internodes or of two internodes separated by a normal internode were more than the sum of the effects of demyelination of each internode individually.5. Propagation across a severely demyelinated internode was blocked with an increase in internal sodium concentration which had a trivial effect on conduction in a normal fibre.6. Propagation across a severely demyelinated internode was blocked with increased temperature at a temperature at which propagation proceeds normally across normal internodes.7. The similarity between the findings of the computer simulations and the experimental findings in demyelinated fibres is discussed.

Studies on the Relation of the Leaves to the Roots in Rice Plant viewed from the Vascular Connection between them

Some experiments were carried out to make clear the relation between the leaves and the The results obtained are summarized as follows: 1) As shown in Fig. 1, adventitious root primordia were initiated at two levels in the nodal region. The root primordia initiated at the basal part of internode are called roots for convenience sake, and the other ones at the disc of insertion of leaf are called roots. The upper root primordia at a given nodal region were initiated earlier than the lower ones at the disc of insertion of leaf above, and then both the primordia were finished the increase in number at about the same time (Fig. 2). 2) In nodal region, the upper root primordia were initiated from the median side to the wing side of the leaf above, and the lower root primordia, on the contrary, were initiated from the opposite side (Fig. 3 and 4). 3) As shown in Fig. 5, the degree of the elongationan of root primodia in nodal region showed the same tendency as the order of the initiation of root primordia. 4) After the emergence of root from the nodal region, as shown in Fig. 5, the growth was found similar to the results mentioned above. From the results described above, the reason of phyton concept is interesting to the writer.

Studies on the Digestion for Bamboo Pulp (1st report)

(I) Analyses : Bamboo is the more heterogeneous material chemically as well as structurally and generally inferior cellulose content to wood. Chemically analysing, the more valuable parts of bamboo for paper pulp are internodes than nodes, and outerparts than innerparts of the stems.(II) Cooking of internodes : In the preparation of stock, internodes have been splitted into 4 layers in thickness to the growing direction of stems, cut each layer to 1.51.8 cms and chipped to the size of (1.5 1.8)2× (0.10.2) cms. I have tried the cooking of 4 layers respectively using some chemicals of the same kind and quantities, and researched into the differences from cooking operation, pulp yield and pulp quantities of each layer.a) Ammonium hydroxide and ammonium monosulphite cooking : When the cooking takes place 3 hrs at maximum temperature 170°C respectively, outerlayer consumes smaller percentage of chemicals and outerlayer pulp is more chlorine requirement than innerlayer. In other words, the pulping velocity of cortial part is very slower than others.b) Ammonium monosulphite cooking : The cooking takes place at high temperature as well as alkaline process. But near the end of the cooking that sulphur dioxide content of the liquor is less than 0.5 percent may be subjected to the burning reaction (difference from sodium monosulphite cooking).In this case, both the pulp and the liquor darken and the pulp is somewhat degraded. To avoid this reaction, an excess of sulphur dioxide content and at least 4.04.5 of pH value should be maintained in the cooking liquor. High unbleached brightness and high yield of pulp result from this cooking as well as sulphite cooking.c) Ammonium bisulphite cooking : The cooking operation generally follows to sulphite cooking, and it has taken place at temperature rising time 3 hrs and maximum temperature 145°C at these experiments.d) Ammonium base sulphite cooking : During the first 5 hrs of sulphite cooking temperature has been raised slowly and precautions being taken that the chips are completely impregnated with cooking liquor, and afterwards it has been at 140°C.To summerize, the obtained general results show as follows :i) NH3 consumption (evolved by boiled solution of caustic soda) is very little in sulphite cooking, and a little in bisulphite cooking. But when ammonium monosulphite cooking or ammomium monosulphite and hydroxide cooking takes place, NH3 consumption is increased distinctly.ii) As compared of pulp qualities in each pulping by the same chlorine consumption pulp, sulphite pulp is the highest α-cellulose content and the least β-cellulose content. In order of sulphite, bisulphite, monosulphite and monosulphite and hydroxide cooking, α-cellulose content is gradually increased but β-cellulose content is decreased.iii) In these cookings, nonuniform cooking takes place and pulp qualities resulting from these cooks for each parts of internodes would be varied in chlorine consumption.e) But in kraft process, the cooking takes place uniformly and there is little difference between chlorine consumption pulp of each layer.