Expression of three phenylpropanoid pathway genes in Scots pine (Pinus sylvestris L.) in open-pollinated families with differing relative wood densities during early and late wood formation

Abstract Wood volume and quality are the most important aspects of commercial forestry production, and studies of wood formation are important in order to increase the value and efficiency of forestry production. The phenylpropanoid pathway produces various compounds with diverse functions both for plant defence against biotic and abiotic stress as well as structural development. One of the main roles is monolignol production for lignin biosynthesis, which is a crucial aspect of wood formation. For this study three candidate genes involved in lignin biosynthesis were selected: phenylalanine ammonialyase (PAL1), cinnamyl alcohol dehydrogenase (CAD) and cinnamoyl-CoA reductase (CCR). Candidate gene expression was analysed in selected individuals with high and low wood density from open-pollinated Scots pine families during early wood (EW) and late wood (LW) formation and correlation between expression of these genes, total lignin content, and wood density was determined. Wood density values for analysed trees were similar within tree families but differed significantly between families with high and low wood density (p=1,06E-20). Wood density was slightly negatively correlated with lignin content (r=-0.36, p=0.038), but only in individuals in the high density wood group. In trees with low wood density, expression of the CAD gene was significantly lower in late wood formation compared to early wood (p=0.00179). In trees with high wood density, expression of the PAL1 gene was five times higher during early wood formation compared to late wood formation. A positive correlation was detected between PAL1 and CCR gene expression during early wood formation (r=0.804) and late wood formation (r=0.466).

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Cinnamate-4-Hydroxylase Gene Is Involved in the Step of Lignin Biosynthesis in Chinese White Pear

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.140.6.573 ◽

2015 ◽

Vol 140 (6) ◽

pp. 573-579 ◽

Cited By ~ 8

Author(s):

Shutian Tao ◽

Danyang Wang ◽

Cong Jin ◽

Wei Sun ◽

Xing Liu ◽

...

Keyword(s):

Gene Expression ◽

Lignin Content ◽

Lignin Biosynthesis ◽

Enzymatic Reactions ◽

Cell Content ◽

Stone Cell ◽

Chinese White ◽

Essential Enzyme ◽

Main Component ◽

Lignin Metabolism

Lignin is the main component of stone cells, and stone cell content is one of the crucial factors for fruit quality in chinese white pear (Pyrus ×bretschneideri). The lignin biosynthesis pathway is complex and involves many enzymatic reactions. Cinnamate-4-hydroxylase [C4H (EC.1.14.13.11)] is an essential enzyme in lignin metabolism. This study was conducted to investigate the effect of bagging on lignin metabolism during fruit development in chinese white pear. The study showed that bagging had little effect on stone cell content, lignin content, C4H activity, and C4H gene expression and that there was a positive correlation between C4H gene expression and lignin content as well as stone cell content. Moreover, a full-length complementary DNA (cDNA) encoding C4H (PbrC4H, GenBank accession number KJ577541.1) was isolated from chinese white pear fruit. The cDNA is 1515 bp long and encodes a protein of 504 amino acids. Sequence alignment suggested that the deduced protein belongs to the P450 gene family and that C4H might be located subcellularly in the cell membrane. The results indicate that bagging cannot change the lignin and stone cell content significantly and that C4H catalyzes a step in lignin biosynthesis. These findings provide certain theoretical references and practical criteria for improving the quality of chinese white pear.

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

Molecules ◽

10.3390/molecules24234338 ◽

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.

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RNA-Seq analysis of differential gene expression in Betula luminifera xylem during the early stages of tension wood formation

PeerJ ◽

10.7717/peerj.5427 ◽

2018 ◽

Vol 6 ◽

pp. e5427 ◽

Cited By ~ 3

Author(s):

Miaomiao Cai ◽

Huahong Huang ◽

Fei Ni ◽

Zaikang Tong ◽

Erpei Lin ◽

...

Keyword(s):

Gene Expression ◽

Tension Wood ◽

Molecular Mechanisms ◽

Southern China ◽

Lignin Biosynthesis ◽

Wood Formation ◽

Cellulose Synthesis ◽

Early Stages ◽

Transcriptional Changes ◽

Betula Luminifera

Background Betula luminifera H. Winkler, which is widely distributed in southern China, is an economically important broadleaf tree species. However, little genomic information of B. luminifera is available, and little is known about the molecular mechanisms of wood formation in this species. Meanwhile, few efforts have focused on investigating the early transcriptional changes during tension wood formation in woody plants. Results A reference transcriptome dataset was first generated containing 45,700 Unigenes, and 35,135 (76.9%) Unigenes were annotated by a BLAST similarity search against four public databases. Then, based on an anatomical investigation, the global gene expression changes during the early stages of tension wood formation were analyzed. Gene expression profiling showed that a total of 13,273 Unigenes were differentially regulated during the early stages of tension wood formation. Most genes involved in cellulose and lignin biosynthesis were highlighted to reveal their biological importance in tension wood formation. In addition, the transcription levels of many genes involved in the auxin response pathway were significantly changed during the early stages of tension wood formation. Furthermore, 18 TFs co-expressed with key enzymes of cellulose synthesis were identified. Conclusions Our results revealed the transcriptional changes associated with TW formation and identified potential key genes in the regulation of this process. These results will help to dissect the molecular mechanism of wood formation and provide key candidate genes for marker-assisted selection in B. luminifera.

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

10.21203/rs.2.11046/v1 ◽

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.

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Wood Formation from the Base to the Crown in Pinus Radiata: Gradients of Tracheid Wall Thickness, Wood Density, Radial Growth Rate and Gene Expression

Plant Molecular Biology ◽

10.1007/s11103-005-5022-9 ◽

2006 ◽

Vol 60 (4) ◽

pp. 565-581 ◽

Cited By ~ 40

Author(s):

Sheree Cato ◽

Lisa McMillan ◽

Lloyd Donaldson ◽

Thomas Richardson ◽

Craig Echt ◽

...

Keyword(s):

Gene Expression ◽

Growth Rate ◽

Wood Density ◽

Wall Thickness ◽

Pinus Radiata ◽

Radial Growth ◽

Wood Formation ◽

Radial Growth Rate

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A Novel NAC Transcription Factor From Eucalyptus, EgNAC141, Positively Regulates Lignin Biosynthesis and Increases Lignin Deposition

Frontiers in Plant Science ◽

10.3389/fpls.2021.642090 ◽

2021 ◽

Vol 12 ◽

Author(s):

YiMing Sun ◽

Chunxue Jiang ◽

Ruiqi Jiang ◽

Fengying Wang ◽

Zhenguo Zhang ◽

...

Keyword(s):

Transcription Factor ◽

Transcription Factors ◽

Lignin Content ◽

Eucalyptus Grandis ◽

Lignin Biosynthesis ◽

Wood Formation ◽

Nac Transcription Factor ◽

Luciferase Assay ◽

Large Set ◽

Biosynthetic Genes

Wood formation is a complicated process under the control of a large set of transcription factors. NAC transcription factors are considered “master switches” in this process. However, few NAC members have been cloned and characterized in Eucalyptus, which is one of the most economically important woody plants. Here, we reported an NAC transcription factor from Eucalyptus grandis, EgNAC141, which has no Arabidopsis orthologs associated with xylogenesis-related processes. EgNAC141 was predominantly expressed in lignin-rich tissues, such as the stem and xylem. Overexpression of EgNAC141 in Arabidopsis resulted in stronger lignification, larger xylem, and higher lignin content. The expression of lignin biosynthetic genes in transgenic plants was significantly higher compared with wild-type plants. The transient expression of EgNAC141 activated the expression of Arabidopsis lignin biosynthetic genes in a dual-luciferase assay. Overall, these results showed that EgNAC141 is a positive regulator of lignin biosynthesis and may help us understand the regulatory mechanism of wood formation.

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Postharvest UV-C irradiation increased the flavonoids and anthocyanins accumulation, phenylpropanoid pathway gene expression, and antioxidant activity in sweet cherries (Prunus avium L.)

Postharvest Biology and Technology ◽

10.1016/j.postharvbio.2021.111490 ◽

2021 ◽

Vol 175 ◽

pp. 111490

Author(s):

Qiang Zhang ◽

Wenbo Yang ◽

Jiechao Liu ◽

Hui Liu ◽

Zhenzhen Lv ◽

...

Keyword(s):

Gene Expression ◽

Antioxidant Activity ◽

Prunus Avium ◽

Phenylpropanoid Pathway ◽

Pathway Gene ◽

Sweet Cherries ◽

Uv C ◽

Phenylpropanoid Pathway Gene ◽

Prunus Avium L

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

Biotechnology for Biofuels ◽

10.1186/s13068-021-01905-1 ◽

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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