Effect of stage of maturity and growth cycle on shearing force and cell wall chemical constituents of alfalfa stems

1996 ◽  
Vol 76 (3) ◽  
pp. 321-328 ◽  
Author(s):  
A. D. Iwaasa ◽  
K. A. Beauchemin ◽  
S. N. Acharya ◽  
J. G. Buchanan-Smith
Keyword(s):  
Cell Wall ◽  
Chemical Constituents ◽  
Growth Cycle ◽  
Stem Diameter ◽  
Stem Segment ◽  
Cellulose Content ◽  
Shearing Force ◽  
Significant Stage ◽  
Early Flower ◽  
Stem Segments

Two experiments were conducted to assess whether stage of maturity and growth cycle affected shearing force of alfalfa (Medicago sativa L.) stems. In both experiments, stem shearing force, diameter and weight were measured at several segments on the stem. In exp. 1, Anchor, Barrier and Vernal alfalfa, at the second and third regrowth were harvested at the early bud stage. Stem weight and diameter were larger at the second regrowth for all stem segments. A numeric trend for lower stem diameter in Vernal compared to Anchor and Barrier was observed. For all stem segments, shearing forces for Anchor and Barrier were lower than for Vernal and shearing force was highest for second regrowth. Vernal had higher NDF, ADF, hemicellulose and cellulose content than other cultivars and ADL was highest at the second regrowth (P < 0.01). In exp. 2, Anchor, Barrier and Vernal alfalfa, in the second production year, were harvested at four stages of maturity, early bud, early flower, late flower and early seed pod. A significant stage of maturity × stem segment effect was observed for shearing force, diameter, and weight. Shearing force, stem diameter and weight measurements generally increased as the plants aged for all stem segments. Quadratic relationships (P < 0.0001) for shearing force stem diameter and weight were observed with increasing stage of maturity for all stem segments. Generally, hemicellulose and lignin contents increased as the plants matured, while cellulose concentrations were variable. Both stage of maturity and growth cycle affected shearing force of alfalfa stems and this was associated with changes in stem diameter, weight and its cell wall chemical constituents. Key words: Alfalfa, stage of maturity, growth cycle, shearing force, cell wall chemical constituents

scholarly journals Shearing force of alfalfa stems: effects of cultivar and shearing site

1999 ◽  
Vol 79 (1) ◽  
pp. 49-55 ◽  
Author(s):  
A. D. Iwaasa ◽  
K. A. Beauchemin ◽  
S. N. Acharya ◽  
J. G. Buchanan-Smith
Keyword(s):  
Cell Wall ◽  
Chemical Constituents ◽  
Sampling Site ◽  
Stem Diameter ◽  
Measuring System ◽  
Cultivar Differences ◽  
Stem Segment ◽  
Shearing Force ◽  
Force Characteristics ◽  
Stem Segments

A 3-yr study was conducted to investigate the effect of shearing position on shearing force characteristics in alfalfa (Medicago sativa L.) stems and to evaluate the relationship between cell wall (CW) chemical constituents and stem shearing force. Stems from plots of 24 alfalfa cultivars were harvested from the second, third and fourth production years. Each stem was divided into three 16-cm segments: top, middle and bottom, and the force required to shear each segment was measured using a modified Ottawa Texture Measuring System. Cultivar by stem segment interactions were significant (P < 0.05) for stem diameter, weight and shearing force. The middle and bottom stem segments were the best sampling site to detect cultivar differences for shearing force. Stem diameter and weight were generally the variables most associated with shearing force for all three stem segments. However, shearing force characteristics for certain cultivars could not be entirely explained by stem diameter or weight and may be affected by CW chemical constituents and/or structural tissues. The ADL concentrations were not consistently correlated to shearing force at the top and bottom segments over the 3 yr. For the bottom stem segment a negative relationship (r = −0.42, P < 0.001) resulted between shearing force and hemicellulose, while a positive relationship (r = 0.40, P < 0.001) resulted between shearing force and cellulose. Key words: Cultivar, environment, shearing force, cell wall chemical constituents

Shearing force of alfalfa stems: Effects of genotype and year interactions

1998 ◽  
Vol 78 (4) ◽  
pp. 719-722
Author(s):  
A. D. Iwaasa ◽  
K. A. Beauchemin ◽  
S. N. Acharya ◽  
J. G. Buchanan-Smith
Keyword(s):  
Cell Wall ◽  
Medicago Sativa ◽  
Key Words ◽  
Chemical Constituents ◽  
Stem Segment ◽  
Shearing Force ◽  
Medicago Sativa L ◽  
Genotype Clustering ◽  
Force Characteristics

Shearing force of alfalfa (Medicago sativa L.) stems was measured to evaluate genotype-by-year interactions. Based on mean shearing force for each stem segment and genotype clustering criteria, several genotypes had similarly shearing forces among years. Therefore, selecting genotypes with desirable shearing force characteristics to improve digestibility or intake potential of forages may be possible. Key words: Genotype, environment, shearing force, cell wall chemical constituents

Shearing force of alfalfa stems as affected by seeding rate

1998 ◽  
Vol 78 (2) ◽  
pp. 273-280 ◽  
Author(s):  
A. D. Iwaasa ◽  
K. A. Beauchemin ◽  
S. N. Acharya ◽  
S. R. Bowley ◽  
J. G. Buchanan-Smith
Keyword(s):  
Cell Wall ◽  
Chemical Constituents ◽  
Physical Characteristics ◽  
Stem Diameter ◽  
Measuring System ◽  
Shearing Force ◽  
Seeding Rate ◽  
Simple Method ◽  
Physical Measurements ◽  
Shearing Strength

Physical properties of forages may provide a simple method of predicting animal voluntary feed intake. Physical measurements, such as shearing force, may indicate the resistance of the forage to particle breakdown during mastication. The objective of this study is to determine the effects of seeding rate on the physical characteristics and cell wall chemical constituents of alfalfa (Medicago sativa L.) stems, and to relate these characteristics to shearing strength. Stems of eight alfalfa cultivars (120, Legend, Multiking 1, OAC Minto, Saranac, Vernal, Vertus, WL320) seeded at 6, 12 and 24 kg ha−1 were harvested in the first and second production years and divided into three 16 cm segments: top, middle and bottom, and the force required to shear each segment was measured using a modified Ottawa Texture Measuring System. For both years, shearing force, segment weight and stem diameter measurements generally decreased as seeding rate increased when measured at the middle and bottom shearing segments on the stem, but this was not observed for the top shearing segment. Effect of seeding rate on differences in segment weight and stem diameter among cultivars was variable among years and stem segments. Concentrations of cell wall constituents in stems were not influenced by seeding rate, and these influenced shearing force to a lesser extent than physical characteristics. Shearing force was directly related to the diameter and weight of the stem. Because of the associations between shearing force and diameter and weight, physical characteristics of the stem may influence forage breakdown during mastication independently, and to a greater extent than cell wall chemical constituents. Key words: Alfalfa, seeding rate, shearing force, cell wall chemical constituents, diameter, weight

scholarly journals Functional Characterisation of the Poplar Atypical Aspartic Protease Gene PtAP66 in Wood Secondary Cell Wall Deposition

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1002
Author(s):  
Shenquan Cao ◽  
Cong Wang ◽  
Huanhuan Ji ◽  
Mengjie Guo ◽  
Jiyao Cheng ◽  
...  
Keyword(s):  
Cell Wall ◽  
Secondary Cell Wall ◽  
Fluorescent Protein ◽  
Secondary Xylem ◽  
Populus Trichocarpa ◽  
Wood Formation ◽  
Protease Gene ◽  
Cellulose Content ◽  
Transcription Analysis ◽  
Functional Characterisation

Secondary cell wall (SCW) deposition is an important process during wood formation. Although aspartic proteases (APs) have been reported to have regulatory roles in herbaceous plants, the involvement of atypical APs in SCW deposition in trees has not been reported. In this study, we characterised the Populus trichocarpa atypical AP gene PtAP66, which is involved in wood SCW deposition. Transcriptome data from the AspWood resource showed that in the secondary xylem of P. trichocarpa, PtAP66 transcripts increased from the vascular cambium to the xylem cell expansion region and maintained high levels in the SCW formation region. Fluorescent signals from transgenic Arabidopsis plant roots and transiently transformed P. trichocarpa leaf protoplasts strongly suggested that the PtAP66-fused fluorescent protein (PtAP66-GFP or PtAP66-YFP) localised in the plasma membrane. Compared with the wild-type plants, the Cas9/gRNA-induced PtAP66 mutants exhibited reduced SCW thickness of secondary xylem fibres, as suggested by the scanning electron microscopy (SEM) data. In addition, wood composition assays revealed that the cellulose content in the mutants decreased by 4.90–5.57%. Transcription analysis further showed that a loss of PtAP66 downregulated the expression of several SCW synthesis-related genes, including cellulose and hemicellulose synthesis enzyme-encoding genes. Altogether, these findings indicate that atypical PtAP66 plays an important role in SCW deposition during wood formation.

scholarly journals Regulation of Cell Wall Synthesis in Avena Stem Segments by Gibberellic Acid

1975 ◽  
Vol 55 (6) ◽  
pp. 1043-1047 ◽  
Author(s):  
Michael J. Montague ◽  
Hiroshi Ikuma
Keyword(s):  
Cell Wall ◽  
Gibberellic Acid ◽  
Cell Wall Synthesis ◽  
Stem Segments

scholarly journals The Dynamics of the Cell Wall Proteome of Developing Alfalfa Stems

Biology ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 60 ◽  
Author(s):  
Sergeant ◽  
Printz ◽  
Guerriero ◽  
Renaut ◽  
Lutts ◽  
...  
Keyword(s):  
Cell Wall ◽  
Apical Region ◽  
Stem Segment ◽  
Burp Domain ◽  
Composition And Structure ◽  
Striking Change ◽  
Stem Development ◽  
Cell Wall Proteome ◽  
Beta Galactosidase

In this study, the cell-wall-enriched subproteomes at three different heights of alfalfa stems were compared. Since these three heights correspond to different states in stem development, a view on the dynamics of the cell wall proteome during cell maturation is obtained. This study of cell wall protein-enriched fractions forms the basis for a description of the development process of the cell wall and the linking cell wall localized proteins with the evolution of cell wall composition and structure. The sequential extraction of cell wall proteins with CaCl2, EGTA, and LiCl-complemented buffers was combined with a gel-based proteome approach and multivariate analysis. Although the highest similarities were observed between the apical and intermediate stem regions, the proteome patterns are characteristic for each region. Proteins that bind carbohydrates and have proteolytic activity, as well as enzymes involved in glycan remobilization, accumulate in the basal stem region. Beta-amylase and ferritin likewise accumulate more in the basal stem segment. Therefore, remobilization of nutrients appears to be an important process in the oldest stem segment. The intermediate and apical regions are sites of cell wall polymer remodeling, as suggested by the high abundance of proteins involved in the remodeling of the cell wall, such as xyloglucan endoglucosylase, beta-galactosidase, or the BURP-domain containing polygalacturonase non-catalytic subunit. However, the most striking change between the different stem parts is the strong accumulation of a DUF642-conserved domain containing protein in the apical region of the stem, which suggests a particular role of this protein during the early development of stem tissues.

scholarly journals Cellulose synthase interactive1- and microtubule-dependent cell wall architecture is required for acid growth in Arabidopsis hypocotyls

2020 ◽  
Vol 71 (10) ◽  
pp. 2982-2994 ◽  
Author(s):  
Xiaoran Xin ◽  
Lei Lei ◽  
Yunzhen Zheng ◽  
Tian Zhang ◽  
Sai Venkatesh Pingali ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Elongation ◽  
Plant Cell Wall ◽  
Cellulose Microfibrils ◽  
Crystalline Cellulose ◽  
Cellulose Content ◽  
Acid Growth ◽  
Cell Wall Assembly ◽  
Dependent Cell ◽  
Cell Wall Architecture

Abstract Auxin-induced cell elongation relies in part on the acidification of the cell wall, a process known as acid growth that presumably triggers expansin-mediated wall loosening via altered interactions between cellulose microfibrils. Cellulose microfibrils are a major determinant for anisotropic growth and they provide the scaffold for cell wall assembly. Little is known about how acid growth depends on cell wall architecture. To explore the relationship between acid growth-mediated cell elongation and plant cell wall architecture, two mutants (jia1-1 and csi1-3) that are defective in cellulose biosynthesis and cellulose microfibril organization were analyzed. The study revealed that cell elongation is dependent on CSI1-mediated cell wall architecture but not on the overall crystalline cellulose content. We observed a correlation between loss of crossed-polylamellate walls and loss of auxin- and fusicoccin-induced cell growth in csi1-3. Furthermore, induced loss of crossed-polylamellate walls via disruption of cortical microtubules mimics the effect of csi1 in acid growth. We hypothesize that CSI1- and microtubule-dependent crossed-polylamellate walls are required for acid growth in Arabidopsis hypocotyls.

scholarly journals Callus induction and regeneration of Alkanna orientalis var. Orientalis and A. sieheana

2019 ◽  
Vol 48 (3) ◽  
pp. 633-640 ◽  
Author(s):  
Cenney Yaman ◽  
Serkan Uranbey ◽  
Hussein Abdullah Ahmed ◽  
Sabahattin Özcan ◽  
Osman Tugay ◽  
...  
Keyword(s):  
Shoot Regeneration ◽  
Callus Induction ◽  
High Frequency ◽  
Stem Segment ◽  
Leaf Base ◽  
Cotyledonary Leaf ◽  
Frequency Variations ◽  
Alkanna Orientalis ◽  
Stem Segments

Callus induction and proliferation of Alkanna orientalis var. orientalis and Alkanna sieheana containing valuable alkannin/shikonin (A/S) derivates were investigated using leaf base and stem segment explants. Stem segments and cotyledonary leaf base of both species were cultured on Murashige and Skoog medium fortified with different concentrations of BAP, Kn, NAA, IAA and IBA for callus induction and shoot regeneration. High frequency reproducible, prolific and compact calli formation was obtained from the stem segments of both species in all media tested. The frequency variations of callus induction and shoot regeneration were discussed in terms of different species, plant growth regulators and explant resources. A. orientalis and A. sieheana may be considered to be alternative plants for the A/S production in vitro.

scholarly journals Exogenous Application of Phytohormones Promotes Growth and Regulates Expression of Wood Formation-Related Genes in Populus simonii × P. nigra

2019 ◽  
Vol 20 (3) ◽  
pp. 792 ◽  
Author(s):  
Hongmei Yuan ◽  
Lijuan Zhao ◽  
Wendong Guo ◽  
Ying Yu ◽  
Lei Tao ◽  
...  
Keyword(s):  
Tissue Specificity ◽  
Expression Patterns ◽  
Wood Formation ◽  
Stem Diameter ◽  
Signal Molecules ◽  
Cellulose Content ◽  
Populus Simonii ◽  
Qpcr Analysis ◽  
Molecular Regulatory Mechanisms ◽  
Indole 3 Acetic Acid

Although phytohormones are known to be important signal molecules involved in wood formation, their roles are still largely unclear. Here, Populus simonii × P. nigra seedlings were treated with different concentrations of exogenous phytohormones, indole-3-acetic acid (IAA), gibberellin (GA3), and brassinosteroid (BR), and the effects of phytohormones on growth were investigated. Next, 27 genes with known roles in wood formation were selected for qPCR analysis to determine tissue-specificity and timing of responses to phytohormone treatments. Compared to the control, most IAA, GA3, and BR concentrations significantly increased seedling height. Meanwhile, IAA induced significant seedling stem diameter and cellulose content increases that peaked at 3 and 30 mg·L−1, respectively. Significant increase in cellulose content was also observed in seedlings treated with 100 mg·L−1 GA3. Neither stem diameter nor cellulose content of seedlings were affected by BR treatment significantly, although slight effects were observed. Anatomical measurements demonstrated improved xylem, but not phloem, development in IAA- and BR-treated seedlings. Most gene expression patterns induced by IAA, GA3, and BR differed among tissues. Many IAA response genes were also regulated by GA3, while BR-induced transcription was weaker and slower in Populus than for IAA and GA3. These results reveal the roles played by phytohormones in plant growth and lay the foundation for exploring molecular regulatory mechanisms of wood formation in Populus.

Sign in / Sign up

Export Citation Format

Share Document