scholarly journals The Sorghum (Sorghum bicolor) Brown Midrib 30 Gene Encodes a Chalcone Isomerase Required for Cell Wall Lignification

2021 ◽  
Vol 12 ◽  
Author(s):  
Hannah M. Tetreault ◽  
Tammy Gries ◽  
Sarah Liu ◽  
John Toy ◽  
Zhanguo Xin ◽  
...  
Keyword(s):  
Cell Wall ◽  
Sorghum Bicolor ◽  
Leaf Tissue ◽  
Histochemical Staining ◽  
Chalcone Isomerase ◽  
Brown Midrib ◽  
Total Anthocyanins ◽  
Altered Cell ◽  
Concentration Loss ◽  
Leaf Midrib

In sorghum (Sorghum bicolor) and other C4 grasses, brown midrib (bmr) mutants have long been associated with plants impaired in their ability to synthesize lignin. The brown midrib 30 (Bmr30) gene, identified using a bulk segregant analysis and next-generation sequencing, was determined to encode a chalcone isomerase (CHI). Two independent mutations within this gene confirmed that loss of its function was responsible for the brown leaf midrib phenotype and reduced lignin concentration. Loss of the Bmr30 gene function, as shown by histochemical staining of leaf midrib and stalk sections, resulted in altered cell wall composition. In the bmr30 mutants, CHI activity was drastically reduced, and the accumulation of total flavonoids and total anthocyanins was impaired, which is consistent with its function in flavonoid biosynthesis. The level of the flavone lignin monomer tricin was reduced 20-fold in the stem relative to wild type, and to undetectable levels in the leaf tissue of the mutants. The bmr30 mutant, therefore, harbors a mutation in a phenylpropanoid biosynthetic gene that is key to the interconnection between flavonoids and monolignols, both of which are utilized for lignin synthesis in the grasses.

Ultrastructure and Senescence in an Achloroplastic Mutant of Hordeum vulgare L. cv. Dyan

1992 ◽  
Vol 50 (1) ◽  
pp. 844-845
Author(s):  
R.H.M. Cross ◽  
C.E.J. Botha ◽  
A.K. Cowan ◽  
B.J. Hartley
Keyword(s):  
Cell Wall ◽  
Hordeum Vulgare ◽  
Leaf Tissue ◽  
Ultrastructural Changes ◽  
Hordeum Vulgare L ◽  
Mesophyll Cells ◽  
Lethal Mutant ◽  
Cytoplasmic Matrix ◽  
Close Proximity ◽  
Pinocytotic Vesicles

Senescence is an ordered degenerative process leading to death of individual cells, organs and organisms. The detection of a conditional lethal mutant (achloroplastic) of Hordeum vulgare has enabled us to investigate ultrastructural changes occurring in leaf tissue during foliar senescence.Examination of the tonoplast structure in six and 14 day-old mutant tissue revealed a progressive degeneration and disappearance of the membrane, apparently starting by day six in the vicinity of the mitochondria associated with the degenerating proplastid (Fig. 1.) where neither of the plastid membrane leaflets is evident (arrows, Fig. 1.). At this stage there was evidence that the mitochondrial membranes were undergoing retrogressive changes, coupled with disorganization of cristae (Fig. 2.). Proplastids (P) lack definitive prolamellar bodies. The cytoplasmic matrix is largely agranular, with few endoplasmic reticulum (ER) cisternae or polyribosomal aggregates. Interestingly, large numbers of actively-budding dictysomes, associated with pinocytotic vesicles, were observed in close proximity to the plasmalemma of mesophyll cells (Fig. 3.). By day 14 however, mesophyll cells showed almost complete breakdown of subcellular organelle structure (Fig. 4.), and further evidence for the breakdown of the tonoplast. The final stage of senescence is characterized by the solubilization of the cell wall due to expression and activity of polygalacturonase and/or cellulose. The presence of dictyosomes with associated pinocytotic vesicles formed from the mature face, in close proximity to both the plasmalemma and the cell wall, would appear to support the model proposed by Christopherson for the secretion of cellulase. This pathway of synthesis is typical for secretory glycoproteins.

CO2 enrichment leads to altered cell wall composition in plants of Pfaffia glomerata (Spreng.) Pedersen (Amaranthaceae)

2021 ◽  
Author(s):  
Eliza Louback ◽  
Diego Silva Batista ◽  
Tiago Augusto Rodrigues Pereira ◽  
Talita Cristina Mamedes-Rodrigues ◽  
Tatiane Dulcineia Silva ◽  
...  
Keyword(s):  
Cell Wall ◽  
Co2 Enrichment ◽  
Cell Wall Composition ◽  
Pfaffia Glomerata ◽  
Altered Cell

scholarly journals PENGARUH INOKULAN BAKTERI ASAM LAKTAT DAN ADITIF TERHADAP KUALITAS DAN KARAKTERISTIK SILASE SORGUM MUTAN 2 1 BROWN MIDRIB (Sorghum bicolor L. Moench)

Pastura ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 40
Author(s):  
R. Sriagtula ◽  
I. Martaguri ◽  
J. Hellyward ◽  
S. Sowmen
Keyword(s):  
Sorghum Bicolor ◽  
Brown Midrib ◽  
Duncan Multiple Range Test ◽  
Sorghum Bicolor L ◽  
Range Test

Penelitian ini bertujuan untuk mengobservasi pengaruh penambahan inokulasi bakteri asam laktat (BAL) dan aditif terhadap kualitas dan karakterietik silase whole crop sorgum mutan brown midrib (Sorghum bicolor L. Moench) galur Patir 3.7 yang dipanen pada fase soft dough. Penelitian dilaksanakan secara eksperimen menggunakan rancangan acak lengkap pola faktorial dengan 4 ulangan. Faktor A yaitu A1 = tanpa BAL, A2= penambahan BAL. Faktor B terdiri dari B1= tanpa aditif, B2= dedak, B3= jagung. Sumber BAL yang digunakan berasal dari inokulan komersil dari minuman fermentasi merk Yakult dengan dosis 1 ml (v/w) atau 11×109 CFU/ml/berat segar. Aditif terdiri dari dedak padi dan jagung halus digunakan sebanyak 3% (g/g)/berat segar. Parameter yang diamati adalah karakteristik dan kualitas silase meliputi nilai pH, nilai fleigh (NF), kandungan bahan kering (BK), protein kasar (PK), serat kasar (SK), lemak kasar (LK) dan Abu. Data dianalisis berdasarkan analisis keragaman menurut Duncan Multiple Range Test (DMRT). Hasil penelitian menunjukkan bahwa tidak terdapat interaksi (P>0,05) antara penambahan BAL dan aditif terhadap pH, NF, BK, PK, SK, LK dan abu, sedangkan faktor tunggal adititif memberikan pengaruh berbeda nyata (P<0,05) lebih tinggi terhadap kandungan BK silase whole crop sorgum mutan BMR. Dari penelitian ini dapat disimpulkan bahwa secara umum penambahan inokulan BAL dan aditif menghasilkan karakteristik dan kualitas silase yang sama, namun demikian penambahan dedak padi dan jagung halus menghasilkan BK silase yang lebih tinggi dibanding tanpa BAL dan aditif. Kata kunci: aditif, BAL, brown midrib, silase, sorgum

A freeze-etch study of plant cell walls for ectodesmata

1974 ◽  
Vol 52 (9) ◽  
pp. 2033-2036 ◽  
Author(s):  
N. C. Lyon ◽  
W. C. Mueller
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Leaf Tissue ◽  
Physicochemical Characteristics ◽  
Outer Cell ◽  
Plantago Major ◽  
Plant Cell Walls ◽  
Phaseolus Vulgaris L ◽  
Epidermal Cell Wall ◽  
Outer Cell Wall

Leaf tissue of Phaseolus vulgaris L. and Plantago major L. was prepared by the freeze-etch technique and examined in the electron microscope for the presence of ectodesmata. No structures analagous to ectodesmata observed with light microscopy could be found in freeze-etched preparations of chemically unfixed material or in material fixed only in glutaraldehyde. Objects appearing as broad, shallow, granular areas in the epidermal cell wall beneath the cuticle were observed in leaf replicas after fixation in complete sublimate fixative, the acid components of the sublimate fixative, or mercuric chloride alone. Because of their distribution and location, these objects can be considered analagous to ectodesmata observed by light microscopists. Because these areas occur only in chemically fixed walls and are localized within the walls in discrete areas, their presence supports the contention that ectodesmata are sites in the outer cell wall with defined physicochemical characteristics.

scholarly journals Downregulation of p‐COUMAROYL ESTER3‐HYDROXYLASEin rice leads to altered cell wall structures and improves biomass saccharification

2018 ◽  
Vol 95 (5) ◽  
pp. 796-811 ◽  
Author(s):  
Yuri Takeda ◽  
Yuki Tobimatsu ◽  
Steven D. Karlen ◽  
Taichi Koshiba ◽  
Shiro Suzuki ◽  
...  
Keyword(s):  
Cell Wall ◽  
Biomass Saccharification ◽  
Wall Structures ◽  
Altered Cell

Reduced photosynthesis in Arabidopsis thaliana atpme17.2 and atpae11.1 mutants is associated to altered cell wall composition

2020 ◽  
Author(s):  
Margalida Roig‐Oliver ◽  
Catherine Rayon ◽  
Romain Roulard ◽  
François Fournet ◽  
Josefina Bota ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Cell Wall Composition ◽  
Altered Cell

scholarly journals Genome-Wide Identification, Characterization and Expression Patterns of the Pectin Methylesterase Inhibitor Genes in Sorghum bicolor

Genes ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 755
Author(s):  
Angyan Ren ◽  
Rana Ahmed ◽  
Huanyu Chen ◽  
Linhe Han ◽  
Jinhao Sun ◽  
...  
Keyword(s):  
Cell Wall ◽  
Sorghum Bicolor ◽  
Stress Responses ◽  
Plant Cell Wall ◽  
Defense Mechanism ◽  
Expression Patterns ◽  
Pectin Methylesterase ◽  
Cell Wall Modification ◽  
Pectin Methylesterase Inhibitor ◽  
Inhibitor Genes

Cell walls are basically complex with dynamic structures that are being involved in several growth and developmental processes, as well as responses to environmental stresses and the defense mechanism. Pectin is secreted into the cell wall in a highly methylesterified form. It is able to perform function after the de-methylesterification by pectin methylesterase (PME). Whereas, the pectin methylesterase inhibitor (PMEI) plays a key role in plant cell wall modification through inhibiting the PME activity. It provides pectin with different levels of degree of methylesterification to affect the cell wall structures and properties. The PME activity was analyzed in six tissues of Sorghum bicolor, and found a high level in the leaf and leaf sheath. PMEI families have been identified in many plant species. Here, a total of 55 pectin methylesterase inhibitor genes (PMEIs) were identified from S. bicolor whole genome, a more detailed annotation of this crop plant as compared to the previous study. Chromosomal localization, gene structures and sequence characterization of the PMEI family were analyzed. Moreover, cis-acting elements analysis revealed that each PMEI gene was regulated by both internal and environmental factors. The expression patterns of each PMEI gene were also clustered according to expression pattern analyzed in 47 tissues under different developmental stages. Furthermore, some SbPMEIs were induced when treated with hormonal and abiotic stress. Taken together, these results laid a strong foundation for further study of the functions of SbPMEIs and pectin modification during plant growth and stress responses of cereal.

scholarly journals The Proline-Rich Family Protein EXTENSIN33 Is Required for Etiolated Arabidopsis thaliana Hypocotyl Growth

2020 ◽  
Vol 61 (6) ◽  
pp. 1191-1203 ◽  
Author(s):  
Malgorzata Zdanio ◽  
Agnieszka Karolina Boron ◽  
Daria Balcerowicz ◽  
Sébastjen Schoenaers ◽  
Marios Nektarios Markakis ◽  
...  
Keyword(s):  
Cell Wall ◽  
Reverse Genetics ◽  
Constant Load ◽  
Hypocotyl Growth ◽  
Native Promoter ◽  
Family Protein ◽  
Altered Cell ◽  
The Moment ◽  
Elongation Phase ◽  
Mutant Lines

Abstract Growth of etiolated Arabidopsis hypocotyls is biphasic. During the first phase, cells elongate slowly and synchronously. At 48 h after imbibition, cells at the hypocotyl base accelerate their growth. Subsequently, this rapid elongation propagates through the hypocotyl from base to top. It is largely unclear what regulates the switch from slow to fast elongation. Reverse genetics-based screening for hypocotyl phenotypes identified three independent mutant lines of At1g70990, a short extensin (EXT) family protein that we named EXT33, with shorter etiolated hypocotyls during the slow elongation phase. However, at 72 h after imbibition, these dark-grown mutant hypocotyls start to elongate faster than the wild type (WT). As a result, fully mature 8-day-old dark-grown hypocotyls were significantly longer than WTs. Mutant roots showed no growth phenotype. In line with these results, analysis of native promoter-driven transcriptional fusion lines revealed that, in dark-grown hypocotyls, expression occurred in the epidermis and cortex and that it was strongest in the growing part. Confocal and spinning disk microscopy on C-terminal protein-GFP fusion lines localized the EXT33-protein to the ER and cell wall. Fourier-transform infrared microspectroscopy identified subtle changes in cell wall composition between WT and the mutant, reflecting altered cell wall biomechanics measured by constant load extensometry. Our results indicate that the EXT33 short EXT family protein is required during the first phase of dark-grown hypocotyl elongation and that it regulates the moment and extent of the growth acceleration by modulating cell wall extensibility.

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