scholarly journals Lignin biosynthesis regulated by the antisense 4CL gene in alfalfa

2018 ◽  
Vol 54 (No. 1) ◽  
pp. 26-29
Author(s):  
J. Meng ◽  
C. Li ◽  
M. Zhao ◽  
C. Wang ◽  
Y. Ru ◽  
...  
Keyword(s):  
Transgenic Plant ◽  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Wild Type Plant ◽  
Test Results ◽  
Wild Type ◽  
Forage Crops ◽  
Amorpha Fruticosa ◽  
Stems And Leaves ◽  
Second Year

The Antisense 4CL gene was transfected into alfalfa through Agrobacterium-mediated transfer. The test results indicated that the antisense 4CL gene was successfully integrated into the genome DNA of alfalfa and was stably transmitted to the offspring. Compared to the wild-type plants, the lignin content of T<sub>0</sub> and T<sub>1</sub> generation plants was reduced by 45.77% and 31.97%, respectively; there were no significant differences in height and weight of T<sub>0</sub> and T<sub>1</sub> plants, compared to the wild-type plants. However, the transgenic plant differed from the wild-type plant by softer stems and leaves, larger leaves, fewer flowers and a fewer seeds. The T<sub>0</sub> line was susceptible to disease infection, but significantly improved in the second year. The results suggest that the 4CL gene from Amorpha fruticosa can be used to regulate lignin biosynthesis in transgenic forage crops.

Effects of the orange lemma (rob1) mutant line of barley cv. ‘Optic’ compared with its wild-type on the ruminal microbiome and fermentation tested with the rumen simulation technique

2019 ◽  
Vol 70 (9) ◽  
pp. 789
Author(s):  
F. Klevenhusen ◽  
C. Emsenhuber ◽  
H. Grausgruber ◽  
R. M. Petri ◽  
Q. Zebeli
Keyword(s):  
Fruit Development ◽  
Lignin Content ◽  
Stem Elongation ◽  
Nutrient Digestibility ◽  
Mutant Line ◽  
Ruminal Fermentation ◽  
Grain Development ◽  
Wild Type ◽  
Forage Crops ◽  
Barley Genotypes

The use of cereals as forage crops is limited due to the high lignin content in the cell walls reducing nutrient digestibility. Recent research has focused on reducing lignification in forage crops through gene mutations. This study investigated the ruminal fermentation characteristics of a barley mutation (orange lemma), which is associated with a lower lignin content, using the in vitro ruminal fermentation system (RUSITEC). Two-rowed spring barley cv. ‘Optic’ and its ethyl methane sulfonate (EMS)-induced orange lemma (rob1) mutant line were harvested at both stem elongation and early fruit development and incubated in the RUSITEC system. Gas production, concentrations of short-chain fatty acids (SCFA) and ammonia and the nutrient degradation of the plants after 48 h incubation were investigated. Additional samples were analysed for microbial composition using MiSeq sequencing technology. In general, acid detergent lignin (ADL) was higher at early grain filling than stem elongation. ADL was lower in the mutant line than in the wild type at both stem elongation (13.9% vs 18.5%) and early grain development (26.0% vs 28.6%; dry matter basis). This was reflected in increased ruminal degradation of neutral detergent fibre (61.7% vs 53.7%; P &lt; 0.001) when harvested at stem elongation, but not at the later stage. In contrast, methane formation was lower with rob1 than ‘Optic’ (P = 0.002), especially when harvested at stem elongation. No difference was seen in protein degradation between the barley genotypes. The fermentation SCFA profile did not differ between barley genotypes when harvested at stem elongation, but at early fruit development more acetate and less butyrate was produced with rob1. Microbial species richness was lower when barley was incubated at stem elongation compared to fruit development (P &lt; 0.001), which was especially pronounced with rob1 (P = 0.026). The abundance of Bacteroidetes, Synergistetes and Tenericutes was lower when plants harvested at early grain development were incubated compared to the stem elongation stage, whereas the abundance of Cyanobacteria, Elusimicrobia, Fusobacteria, Lentisphaerae, Proteobacteria, Verrucomicrobia and WPS-2 was higher (P &lt; 0.001). In conclusion, most fermentation parameters were affected by vegetation stage and related changes in nutrient composition. However, additional effects of barley genotype were seen on the rumen microbial community structure, SCFA profile and methane production.

scholarly journals The BpMYB4 Transcription Factor From Betula platyphylla Contributes Toward Abiotic Stress Resistance and Secondary Cell Wall Biosynthesis

2021 ◽  
Vol 11 ◽  
Author(s):  
Ying Yu ◽  
Huizi Liu ◽  
Nan Zhang ◽  
Caiqiu Gao ◽  
Liwang Qi ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Abiotic Stress ◽  
Transgenic Plants ◽  
Stress Resistance ◽  
Secondary Cell Wall ◽  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Betula Platyphylla ◽  
Wild Type

The MYB (v-myb avian myeloblastosis viral oncogene homolog) family is one of the largest transcription factor families in plants, and is widely involved in the regulation of plant metabolism. In this study, we show that a MYB4 transcription factor, BpMYB4, identified from birch (Betula platyphylla Suk.) and homologous to EgMYB1 from Eucalyptus robusta Smith and ZmMYB31 from Zea mays L. is involved in secondary cell wall synthesis. The expression level of BpMYB4 was higher in flowers relative to other tissues, and was induced by artificial bending and gravitational stimuli in developing xylem tissues. The expression of this gene was not enriched in the developing xylem during the active season, and showed higher transcript levels in xylem tissues around sprouting and near the dormant period. BpMYB4 also was induced express by abiotic stress. Functional analysis indicated that expression of BpMYB4 in transgenic Arabidopsis (Arabidopsis thaliana) plants could promote the growth of stems, and result in increased number of inflorescence stems and shoots. Anatomical observation of stem sections showed lower lignin deposition, and a chemical contents test also demonstrated increased cellulose and decreased lignin content in the transgenic plants. In addition, treatment with 100 mM NaCl and 200 mM mannitol resulted in the germination rate of the over-expressed lines being higher than that of the wild-type seeds. The proline content in transgenic plants was higher than that in WT, but MDA content was lower than that in WT. Further investigation in birch using transient transformation techniques indicated that overexpression of BpMYB4 could scavenge hydrogen peroxide and O2.– and reduce cell damage, compared with the wild-type plants. Therefore, we believe that BpMYB4 promotes stem development and cellulose biosynthesis as an inhibitor of lignin biosynthesis, and has a function in abiotic stress resistance.

scholarly journals Physiological and transcriptome analysis of indica rice 'MH86' overexpressing OsSPL14

2018 ◽  
Author(s):  
Ling Lian ◽  
Wei He ◽  
Qiu hua Cai ◽  
Hui Zhang ◽  
Cheng rong Ren ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Transgenic Plant ◽  
Transcriptome Analysis ◽  
Indica Rice ◽  
Critical Role ◽  
Lignin Biosynthesis ◽  
Growth Period ◽  
Carotenoid Biosynthesis ◽  
Maturity Stage ◽  
Wild Type Plant

OsSPL14, identified as IDEAL PLANT ARCHITECTURE1 (IPA1) or WEALTHY FARMER'S PANICLE (WFP) gene, plays a critical role in regulating rice plant architecture. Here, the study showed that OsSPL14-overexpression transgenic rice plants had shorter growth period, short-narrow flag leaves, and thick-green leaves. Compared with wild type plant 'MH86', transgenic plants had higher chlorophyll a (Ca), chlorophyll b (Cb) and carotenoid (Cx) content at both seedling and maturity stage. Meanwhile, transcriptome analysis identified 473 up-regulated and 103 down-regulated genes in transgenic plant. The expression of differentially expressed genes (DEGs) involved in carotenoid biosynthesis, abscisic acid (ABA) metabolism and lignin biosynthesis increased significantly. Most of DEGs participated in 'plant hormone signal transduction' and 'starch and sucrose metabolism' are also up-regulated in transgenic plant. In addition, there were higher levels of ABA and gibberellin acid (GA3) in OsSPL14-overexpression transgenic plants. Moreover, the content of culm lignin, cellulose, silicon and potassium all increased dramatically. Thus, these results demonstrate that overexpression of OsSPL14 has influence on leaf development, hormone level and culm composition in rice, which provide more insight into understanding the function of OsSPL14.

scholarly journals Histone Deacetylase HDT1 is Involved in Stem Vascular Development in Arabidopsis

2019 ◽  
Vol 20 (14) ◽  
pp. 3452 ◽  
Author(s):  
Yongzhuo Zhang ◽  
Bin Yin ◽  
Jiaxue Zhang ◽  
Ziyi Cheng ◽  
Yadi Liu ◽  
...  
Keyword(s):  
Histone Deacetylases ◽  
Vascular Tissue ◽  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Cell Number ◽  
Wild Type ◽  
Tracheary Elements ◽  
Fiber Cells ◽  
Cell Proliferation And Differentiation ◽  
Eukaryotic Gene

Histone acetylation and deacetylation play essential roles in eukaryotic gene regulation. HD2 (HD-tuins) proteins were previously identified as plant-specific histone deacetylases. In this study, we investigated the function of the HDT1 gene in the formation of stem vascular tissue in Arabidopsis thaliana. The height and thickness of the inflorescence stems in the hdt1 mutant was lower than that of wild-type plants. Paraffin sections showed that the cell number increased compared to the wild type, while transmission electron microscopy showed that the size of individual tracheary elements and fiber cells significantly decreased in the hdt1 mutant. In addition, the cell wall thickness of tracheary elements and fiber cells increased. We also found that the lignin content in the stem of the hdt1 mutants increased compared to that of the wild type. Transcriptomic data revealed that the expression levels of many biosynthetic genes related to secondary wall components, including cellulose, lignin biosynthesis, and hormone-related genes, were altered, which may lead to the altered phenotype in vascular tissue of the hdt1 mutant. These results suggested that HDT1 is involved in development of the vascular tissue of the stem by affecting cell proliferation and differentiation.

scholarly journals CAND2/PMTR1 Is Required for Melatonin-Conferred Osmotic Stress Tolerance in Arabidopsis

2021 ◽  
Vol 22 (8) ◽  
pp. 4014
Author(s):  
Lin-Feng Wang ◽  
Ting-Ting Li ◽  
Yu Zhang ◽  
Jia-Xing Guo ◽  
Kai-Kai Lu ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Stress Tolerance ◽  
Wild Type Plant ◽  
Wild Type ◽  
Melatonin Receptor ◽  
Ros Scavenging ◽  
Exogenous Melatonin ◽  
Osmotic Stress Tolerance ◽  
Osmotic Stress Response ◽  
In The Wild

Osmotic stress severely inhibits plant growth and development, causing huge loss of crop quality and quantity worldwide. Melatonin is an important signaling molecule that generally confers plant increased tolerance to various environmental stresses, however, whether and how melatonin participates in plant osmotic stress response remain elusive. Here, we report that melatonin enhances plant osmotic stress tolerance through increasing ROS-scavenging ability, and melatonin receptor CAND2 plays a key role in melatonin-mediated plant response to osmotic stress. Upon osmotic stress treatment, the expression of melatonin biosynthetic genes including SNAT1, COMT1, and ASMT1 and the accumulation of melatonin are increased in the wild-type plants. The snat1 mutant is defective in osmotic stress-induced melatonin accumulation and thus sensitive to osmotic stress, while exogenous melatonin enhances the tolerance of the wild-type plant and rescues the sensitivity of the snat1 mutant to osmotic stress by upregulating the expression and activity of catalase and superoxide dismutase to repress H2O2 accumulation. Further study showed that the melatonin receptor mutant cand2 exhibits reduced osmotic stress tolerance with increased ROS accumulation, but exogenous melatonin cannot revert its osmotic stress phenotype. Together, our study reveals that CADN2 functions necessarily in melatonin-conferred osmotic stress tolerance by activating ROS-scavenging ability in Arabidopsis.

scholarly journals Degradation of trinitrotoluene by transgenic nitroreductase in Arabidopsis plants

2018 ◽  
Vol 64 (No. 8) ◽  
pp. 379-385 ◽  
Author(s):  
Zhu Bo ◽  
Han Hongjuan ◽  
Fu Xiaoyan ◽  
Li Zhenjun ◽  
Gao Jianjie ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Transgenic Arabidopsis ◽  
Environmental Pollutant ◽  
Specific Rate ◽  
Wild Type Plant ◽  
Wild Type ◽  
Fresh Weight ◽  
Human Carcinogen ◽  
Specific Rate Constant ◽  
Nitroreductase Activity

The explosive 2,4,6-trinitrotoluene (TNT) is a highly toxic and persistent environmental pollutant. TNT is toxic to many organisms, it is known to be a potential human carcinogen, and is persistent in the environment. This study presents a system of phytoremediation by Arabidopsis plants developed on the basis of overexpression of NAD(P)H-flavin nitroreductase (NFSB) from the Sulfurimonas denitrificans DSM1251. The resulting transgenic Arabidopsis plants demonstrated significantly enhanced TNT tolerance and a strikingly higher capacity to remove TNT from their media. The highest specific rate constant of TNT disappearance rate was 1.219 and 2.297 mL/g fresh weight/h for wild type and transgenic plants, respectively. Meanwhile, the nitroreductase activity in transgenic plant was higher than wild type plant. All this indicates that transgenic plants show significantly enhanced tolerances to TNT; transgenic plants also exhibit strikingly higher capabilities of removing TNT from their media and high efficiencies of transformation.

scholarly journals Targeting hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase for lignin modification in Brachypodium distachyon

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Juan Carlos Serrani-Yarce ◽  
Luis Escamilla-Trevino ◽  
Jaime Barros ◽  
Lina Gallego-Giraldo ◽  
Yunqiao Pu ◽  
...  
Keyword(s):  
Negative Impact ◽  
Lignin Content ◽  
Brachypodium Distachyon ◽  
Lignin Biosynthesis ◽  
Reverse Direction ◽  
Wall Structure ◽  
Kinetic Properties ◽  
Loss Of Function ◽  
Down Regulation ◽  
Lignin Modification

Abstract Background Hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase (HCT) is a central enzyme of the so-called “esters” pathway to monolignols. As originally envisioned, HCT functions twice in this pathway, to form coumaroyl shikimate and then, in the “reverse” direction, to convert caffeoyl shikimate to caffeoyl CoA. The discovery of a caffeoyl shikimate esterase (CSE) that forms caffeic acid directly from caffeoyl shikimate calls into question the need for the reverse HCT reaction in lignin biosynthesis. Loss of function of HCT gives severe growth phenotypes in several dicot plants, but less so in some monocots, questioning whether this enzyme, and therefore the shikimate shunt, plays the same role in both monocots and dicots. The model grass Brachypodium distachyon has two HCT genes, but lacks a classical CSE gene. This study was therefore conducted to evaluate the utility of HCT as a target for lignin modification in a species with an “incomplete” shikimate shunt. Results The kinetic properties of recombinant B. distachyon HCTs were compared with those from Arabidopsis thaliana, Medicago truncatula, and Panicum virgatum (switchgrass) for both the forward and reverse reactions. Along with two M. truncatula HCTs, B. distachyon HCT2 had the least kinetically unfavorable reverse HCT reaction, and this enzyme is induced when HCT1 is down-regulated. Down regulation of B. distachyon HCT1, or co-down-regulation of HCT1 and HCT2, by RNA interference led to reduced lignin levels, with only modest changes in lignin composition and molecular weight. Conclusions Down-regulation of HCT1, or co-down-regulation of both HCT genes, in B. distachyon results in less extensive changes in lignin content/composition and cell wall structure than observed following HCT down-regulation in dicots, with little negative impact on biomass yield. Nevertheless, HCT down-regulation leads to significant improvements in biomass saccharification efficiency, making this gene a preferred target for biotechnological improvement of grasses for bioprocessing.

scholarly journals Hypolignification: A Decisive Factor in the Development of Hyperhydricity

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2625
Author(s):  
Nurashikin Kemat ◽  
Richard G. F. Visser ◽  
Frans A. Krens
Keyword(s):  
Cell Wall ◽  
Lignin Content ◽  
Coumaric Acid ◽  
Wild Type ◽  
Higher Plant ◽  
Gene Coding ◽  
Phenylpropanoid Biosynthesis ◽  
Total Lignin ◽  
Total Lignin Content

One of the characteristics of hyperhydric plants is the reduction of cell wall lignification (hypolignification), but how this is related to the observed abnormalities of hyperhydricity (HH), is still unclear. Lignin is hydrophobic, and we speculate that a reduction in lignin levels leads to more capillary action of the cell wall and consequently to more water in the apoplast. p-coumaric acid is the hydroxyl derivative of cinnamic acid and a precursor for lignin and flavonoids in higher plant. In the present study, we examined the role of lignin in the development of HH in Arabidopsis thaliana by checking the wild-types (Ler and Col-0) and mutants affected in phenylpropanoid biosynthesis, in the gene coding for cinnamate 4-hydroxylase, C4H (ref3-1 and ref3-3). Exogenously applied p-coumaric acid decreased the symptoms of HH in both wild-type and less-lignin mutants. Moreover, the results revealed that exogenously applied p-coumaric acid inhibited root growth and increased the total lignin content in both wild-type and less-lignin mutants. These effects appeared to diminish the symptoms of HH and suggest an important role for lignin in HH.

scholarly journals Distinct and overlapping functions of Miscanthus sinensis MYB transcription factors SCM1 and MYB103 in lignin biosynthesis

2019 ◽  
Author(s):  
Philippe Golfier ◽  
Faride Unda ◽  
Emily K. Murphy ◽  
Jianbo Xie ◽  
Feng He ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcriptional Regulation ◽  
Secondary Cell Wall ◽  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Miscanthus Sinensis ◽  
Cell Wall Formation ◽  
Transcriptional Responses ◽  
Secondary Cell Wall Formation ◽  
Wall Formation

AbstractCell wall recalcitrance is a major constraint for the exploitation of lignocellulosic biomass as renewable resource for energy and bio-based products. Transcriptional regulators of the lignin biosynthetic pathway represent promising targets for tailoring lignin content and composition in plant secondary cell walls. A wealth of research in model organisms has revealed that transcriptional regulation of secondary cell wall formation is orchestrated by a hierarchical transcription factor (TF) network with NAC TFs as master regulators and MYB factors in the lower tier regulators. However, knowledge about the transcriptional regulation of lignin biosynthesis in lignocellulosic feedstocks, such as Miscanthus, is limited. Here, we characterized two Miscanthus MYB TFs, MsSCM1 and MsMYB103, and compared their transcriptional impact with that of the master regulator MsSND1. In Miscanthus leaves MsSCM1 and MsMYB103 are expressed at growth stages associated with lignification. Ectopic expression of MsSCM1 and MsMYB103 in tobacco leaves was sufficient to trigger secondary cell wall deposition with distinct sugar and lignin composition. Moreover, RNA-seq analysis revealed that the transcriptional responses to MsSCM1 and MsMYB103 overexpression showed extensive overlap with the response to MsSND1, but were distinct from each other, underscoring the inherent complexity of secondary cell wall formation. Together, MsSCM1 and MsMYB103 represent interesting targets for manipulations of lignin content and composition in Miscanthus towards tailored biomass.

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