Perturbation of lignin biosynthesis pathway in Brassica napus (canola) plants using RNAi

2009 ◽  
Vol 89 (3) ◽  
pp. 441-453 ◽  
Author(s):  
V. -S. Bhinu ◽  
R. Li ◽  
J. Huang ◽  
S. Kaminskyj ◽  
A. Sharpe ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Anatomical Variations ◽  
Feed Utilization ◽  
Biosynthesis Pathway ◽  
Factors Affecting ◽  
Transgenic Seeds ◽  
Vessel Elements ◽  
Negative Effect

Brassica napus meal contains high levels of lignin, which is one of the most important compositional factors affecting feed utilization by ruminants. We attempted to modify the concentration and composition of lignin in B. napus plants using the RNAi approach. Four genes were targeted for silencing by this approach either independently or in combination; caffeic acid O-methyltransferase (COMT), cinnamate 4-hydroxylase (C4H); coumarate 3-hydroxylase (C3H); ferulic acid 5-hydroxylase (F5H). We successfully developed transgenic B. napus lines expressing CaMV35S:C3H-C4H RNAi, CaMV35S:F5H-COMT RNAi, and Cruciferin:COMT RNAi that contained up to 40% less seed lignin in the transgenic seeds compared to the control. Despite successfully achieving suppression of these lignin biosynthesis genes and reduction in lignin content in B. napus seeds, we observed minor phenotypic effects on the transgenic plants. In lines carrying the cruciferin:COMT RNAi construct we observed a decrease in lignin content (40%) in the seed and anatomical variations when stem sections were examined. While our silencing had no major negative effect on plant growth it resulted in deformation of vessel elements, and minor changes in S-units. Taken together, these results clearly show that by employing RNAi strategy, it is possible to alter seed lignin content and composition in a manner non-detrimental to B. napus plants.Key words: Brassica napus, cruciferin, lignin, COMT, RNAi

scholarly journals Overexpression of Pear (Pyrus pyrifolia) CAD2 in Tomato Affects Lignin Content

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2595 ◽  
Author(s):  
Mingtong Li ◽  
Chenxia Cheng ◽  
Xinfu Zhang ◽  
Suping Zhou ◽  
Lixia Li ◽  
...  
Keyword(s):  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Cinnamyl Alcohol Dehydrogenase ◽  
Transformation Method ◽  
Transgenic Tomato ◽  
Pyrus Pyrifolia ◽  
Tomato Plants ◽  
Over Expression ◽  
Transgenic Tomato Plants ◽  
Vessel Elements

PpCAD2 was originally isolated from the ‘Wangkumbae’ pear (Pyrus pyrifolia Nakai), and it encodes for cinnamyl alcohol dehydrogenase (CAD), which is a key enzyme in the lignin biosynthesis pathway. In order to verify the function of PpCAD2, transgenic tomato (Solanum lycopersicum) ‘Micro-Tom’ plants were generated using over-expression constructs via the agrobacterium-mediated transformation method. The results showed that the PpCAD2 over-expression transgenic tomato plant had a strong growth vigor. Furthermore, these PpCAD2 over-expression transgenic tomato plants contained a higher lignin content and CAD enzymatic activity in the stem, leaf and fruit pericarp tissues, and formed a greater number of vessel elements in the stem and leaf vein, compared to wild type tomato plants. This study clearly indicated that overexpressing PpCAD2 increased the lignin deposition of transgenic tomato plants, and thus validated the function of PpCAD2 in lignin biosynthesis.

scholarly journals PpNAC187 Enhances Lignin Synthesis in ‘Whangkeumbae’ Pear (Pyrus pyrifolia) ‘Hard-End’ Fruit

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4338
Author(s):  
Mingtong Li ◽  
Chenxia Cheng ◽  
Xinfu Zhang ◽  
Suping Zhou ◽  
Caihong Wang ◽  
...  
Keyword(s):  
Transgenic Tobacco ◽  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Phenylpropanoid Pathway ◽  
Pyrus Pyrifolia ◽  
Rna Seq ◽  
Pear Fruit ◽  
Nac Transcription Factors ◽  
Vessel Elements ◽  
Leaf Tissues

A disorder in pears that is known as ‘hard-end’ fruit affects the appearance, edible quality, and market value of pear fruit. RNA-Seq was carried out on the calyx end of ‘Whangkeumbae’ pear fruit with and without the hard-end symptom to explore the mechanism underlying the formation of hard-end. The results indicated that the genes in the phenylpropanoid pathway affecting lignification were up-regulated in hard-end fruit. An analysis of differentially expressed genes (DEGs) identified three NAC transcription factors, and RT-qPCR analysis of PpNAC138, PpNAC186, and PpNAC187 confirmed that PpNAC187 gene expression was correlated with the hard-end disorder in pear fruit. A transient increase in PpNAC187 was observed in the calyx end of ‘Whangkeumbae’ fruit when they began to exhibit hard-end symptom. Concomitantly, the higher level of PpCCR and PpCOMT transcripts was observed, which are the key genes in lignin biosynthesis. Notably, lignin content in the stem and leaf tissues of transgenic tobacco overexpressing PpNAC187 was significantly higher than in the control plants that were transformed with an empty vector. Furthermore, transgenic tobacco overexpressing PpNAC187 had a larger number of xylem vessel elements. The results of this study confirmed that PpNAC187 functions in inducing lignification in pear fruit during the development of the hard-end disorder.

scholarly journals Genetic, transcriptional, and regulatory landscape of monolignol biosynthesis pathway in Miscanthus × giganteus

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xiaofei Zeng ◽  
Jiajing Sheng ◽  
Fenglin Zhu ◽  
Tianzi Wei ◽  
Lingling Zhao ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Enzymatic Reactions ◽  
Biosynthesis Pathway ◽  
Miscanthus Giganteus ◽  
Monolignol Biosynthesis ◽  
Essential Knowledge ◽  
Main Component ◽  
Regulatory Landscape

Abstract Background Miscanthus × giganteus is widely recognized as a promising lignocellulosic biomass crop due to its advantages of high biomass production, low environmental impacts, and the potential to be cultivated on marginal land. However, the high costs of bioethanol production still limit the current commercialization of lignocellulosic bioethanol. The lignin in the cell wall and its by-products released in the pretreatment step is the main component inhibiting the enzymatic reactions in the saccharification and fermentation processes. Hence, genetic modification of the genes involved in lignin biosynthesis could be a feasible strategy to overcome this barrier by manipulating the lignin content and composition of M. × giganteus. For this purpose, the essential knowledge of these genes and understanding the underlying regulatory mechanisms in M. × giganteus is required. Results In this study, MgPAL1, MgPAL5, Mg4CL1, Mg4CL3, MgHCT1, MgHCT2, MgC3′H1, MgCCoAOMT1, MgCCoAOMT3, MgCCR1, MgCCR2, MgF5H, MgCOMT, and MgCAD were identified as the major monolignol biosynthetic genes in M. × giganteus based on genetic and transcriptional evidence. Among them, 12 genes were cloned and sequenced. By combining transcription factor binding site prediction and expression correlation analysis, MYB46, MYB61, MYB63, WRKY24, WRKY35, WRKY12, ERF021, ERF058, and ERF017 were inferred to regulate the expression of these genes directly. On the basis of these results, an integrated model was summarized to depict the monolignol biosynthesis pathway and the underlying regulatory mechanism in M. × giganteus. Conclusions This study provides a list of potential gene targets for genetic improvement of lignocellulosic biomass quality of M. × giganteus, and reveals the genetic, transcriptional, and regulatory landscape of the monolignol biosynthesis pathway in M. × giganteus.

PpNAC187 enhances lignin synthesis in ‘Whangkeumbae’ pear (Pyrus pyrifolia) ‘hard-end’ fruit

2019 ◽  
Author(s):  
Mingtong Li ◽  
Chenxia Cheng ◽  
Xinfu Zhang ◽  
Suping Zhou ◽  
Caihong Wang ◽  
...  
Keyword(s):  
Transgenic Tobacco ◽  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Phenylpropanoid Pathway ◽  
Pyrus Pyrifolia ◽  
Rna Seq ◽  
Pear Fruit ◽  
Nac Transcription Factors ◽  
Vessel Elements ◽  
Leaf Tissues

Abstract Background: A disorder in pears known as ‘hard-end’ fruit affects the appearance, edible quality, and market value of pear fruit. To explore the mechanism underlying the formation of hard-end, RNA-Seq was carried out on the calyx end of ‘Whangkeumbae’ pear fruit with and without the hard-end symptom. Result: Results indicated that genes in the phenylpropanoid pathway affecting lignification were up-regulated in hard-end fruit. An analysis of differentially expressed genes (DEGs) identified three NAC transcription factors, and RT-qPCR analysis of PpNAC138, PpNAC186 and PpNAC187 confirmed that PpNAC187 gene expression was correlated with the hard-end disorder in pear fruit. A transient increase in PpNAC187 was observed in the calyx end of ‘Whangkeumbae’ fruit when they began to exhibit hard-end symptom. Concomitantly, the higher level of PpCCR, Pp4CL and PpCOMT transcripts was observed; which are the key genes in lignin biosynthesis. Notably, lignin content in the stem and leaf tissues of transgenic tobacco overexpressing PpNAC187 was significantly higher than in control plants transformed with an empty vector. Furthermore, transgenic tobacco overexpressing PpNAC187 had a larger number of xylem vessel elements. Conclusion: The results of this study confirmed that PpNAC187 functions in inducing lignification in pear fruit during the development of the hard-end disorder.

scholarly journals Overexpression of Cinnamoyl-CoA Reductase 2 in Brassica napus Increases Resistance to Sclerotinia sclerotiorum by Affecting Lignin Biosynthesis

2021 ◽  
Vol 12 ◽  
Author(s):  
Dongxiao Liu ◽  
Jian Wu ◽  
Li Lin ◽  
Panpan Li ◽  
Saifen Li ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Sclerotinia Sclerotiorum ◽  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Normal Growth ◽  
Economic Losses ◽  
Post Inoculation ◽  
Infection Period ◽  
Cinnamoyl Coa Reductase ◽  
Coa Reductase

Sclerotinia sclerotiorum causes severe yield and economic losses for many crop and vegetable species, especially Brassica napus. To date, no immune B. napus germplasm has been identified, giving rise to a major challenge in the breeding of Sclerotinia resistance. In the present study, we found that, compared with a Sclerotinia-susceptible line (J902), a Sclerotinia-resistant line (J964) exhibited better xylem development and a higher lignin content in the stems, which may limit the invasion and spread of S. sclerotiorum during the early infection period. In addition, genes involved in lignin biosynthesis were induced under S. sclerotiorum infection in both lines, indicating that lignin was deposited proactively in infected tissues. We then overexpressed BnaC.CCR2.b, which encodes the first rate-limiting enzyme (cinnamoyl-CoA reductase) that catalyzes the reaction of lignin-specific pathways, and found that overexpression of BnaC.CCR2.b increased the lignin content in the stems of B. napus by 2.28–2.76% under normal growth conditions. We further evaluated the Sclerotinia resistance of BnaC.CCR2.b overexpression lines at the flower-termination stage and found that the disease lesions on the stems of plants in the T2 and T3 generations decreased by 12.2–33.7% and 32.5–37.3% compared to non-transgenic control plants, respectively, at 7days post-inoculation (dpi). The above results indicate that overexpression of BnaC.CCR2.b leads to an increase in lignin content in the stems, which subsequently leads to increased resistance to S. sclerotiorum. Our findings demonstrate that increasing the lignin content in the stems of B. napus is an important strategy for controlling Sclerotinia.

scholarly journals Spatial distribution of the Barbary Partridge (Alectoris barbara) in Sardinia explained by land use and climate

2021 ◽  
Vol 67 (4) ◽  
Author(s):  
Gianpasquale Chiatante ◽  
Marta Giordano ◽  
Anna Vidus Rosin ◽  
Oreste Sacchi ◽  
Alberto Meriggi
Keyword(s):  
Land Use ◽  
Conservation Status ◽  
Distance Sampling ◽  
Strong Relationship ◽  
European Population ◽  
Factors Affecting ◽  
Brood Rearing ◽  
Management Actions ◽  
Negative Effect ◽  
Study Sites

AbstractMore than half of the European population of the Barbary Partridge is in Sardinia; nonetheless, the researches concerning this species are very scarce, and its conservation status is not defined because of a deficiency of data. This research aimed to analyse the habitat selection and the factors affecting the abundance and the density of the Barbary Partridge in Sardinia. We used the data collected over 8 years (between 2004 and 2013) by spring call counts in 67 study sites spread on the whole island. We used GLMM to define the relationships between the environment (topography, land use, climate) both the occurrence and the abundance of the species. Moreover, we estimated population densities by distance sampling. The Barbary Partridge occurred in areas at low altitude with garrigue and pastures, avoiding woodlands and sparsely vegetated areas. We found a strong relationship between the occurrence probability and the climate, in particular, a positive relation with temperature and a negative effect of precipitation, especially in April–May, during brood rearing. Furthermore, dry crops positively affected the abundance of the species. We estimated a density of 14.1 partridges per km2, similar to other known estimates. Our findings are important both because they increase the knowledge concerning this species, which is considered data deficient in Italy, and because they are useful to plan management actions aimed to maintain viable populations if necessary.

Analysis of Single-Vehicle Crash Injury Severities in Urban River-Crossing Road Tunnels

2015 ◽  
Vol 743 ◽  
pp. 526-532 ◽  
Author(s):  
C.M. Jiang ◽  
J.J. Lu ◽  
L.J. Lu
Keyword(s):  
Heavy Vehicles ◽  
Probit Regression ◽  
Factors Affecting ◽  
Explanatory Variables ◽  
Urban Road ◽  
Road Tunnels ◽  
Negative Effect ◽  
Single Vehicle ◽  
Injury Severities ◽  
One Year

Based on the originally unprocessed data from the Official Platform of“110”Alarming Receiving Center (OP110ARC) of Shanghai Public Security Bureau (SPSB), 529 single-vehicle crashes reported during one year and a half which happened at the thirteen urban road tunnels going across the Huangpu River are used in this study. To investigate the factors affecting the crash influence severity levels, ordered probit regression is established. Several categories of factors are considered as explanatory variables in the models. The study finds that the entrance of the tunnels is the site where severe injury crashes trend to occur. Rainy and snowy days impose vehicles and motorists driving via the tunnel sections in danger. Tunnels with a low speed limit (40 km/h in this study) may be not as safe as we thought before. Two-wheel vehicles without sufficient physical protection for its drivers and heavy vehicles also show a negative effect on the operation safety of single-vehicle at these studied tunnels. Alcohol involved drivers are more likely to suffer from a severe crashes and gets badly hurt.

scholarly journals Psychological Factors Affecting Risk Perception of COVID-19: Evidence from Peru and China

2021 ◽  
Vol 18 (12) ◽  
pp. 6513
Author(s):  
Fredy S. Monge-Rodríguez ◽  
He Jiang ◽  
Liwei Zhang ◽  
Andy Alvarado-Yepez ◽  
Anahí Cardona-Rivero ◽  
...  
Keyword(s):  
Risk Perception ◽  
Risk Communication ◽  
Online Survey ◽  
Factors Affecting ◽  
Self Confidence ◽  
Global Pandemic ◽  
Negative Effect ◽  
The Government ◽  
Using Data ◽  
Health Field

COVID-19 has spread around the world, causing a global pandemic, and to date is impacting in various ways in both developed and developing countries. We know that the spread of this virus is through people’s behavior despite the perceived risks. Risk perception plays an important role in decision-making to prevent infection. Using data from the online survey of participants in Peru and China (N = 1594), data were collected between 8 July 31 and August 2020. We found that levels of risk perception are relatively moderate, but higher in Peru compared to China. In both countries, anxiety, threat perception, self-confidence, and sex were found to be significant predictors of risk perception; however, trust in the information received by government and experts was significant only in Peru, whereas self-confidence had a significant negative effect only for China. Risk communication should be implemented through information programs aimed at reducing anxiety and improving self-confidence, taking into consideration gender differences. In addition, the information generated by the government should be based on empirical sources. Finally, the implications for effective risk communication and its impacts on the health field are discussed.

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.

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