Limits...
Transcriptional Profiles of Hybrid Eucalyptus Genotypes with Contrasting Lignin Content Reveal That Monolignol Biosynthesis-related Genes Regulate Wood Composition.

Shinya T, Iwata E, Nakahama K, Fukuda Y, Hayashi K, Nanto K, Rosa AC, Kawaoka A - Front Plant Sci (2016)

Bottom Line: We analyzed genes encoding NAC, WRKY, AP2/ERF, and KNOX transcription factors and found higher transcript levels of these genes in AM380.We also observed increased transcription of some MYB and LIM domain transcription factors in AM380 compared to AM063.All these results show that genes related to monolignol biosynthesis may regulate the wood composition and help maintain the ratio of cellulose and lignin contents in Eucalyptus plants.

View Article: PubMed Central - PubMed

Affiliation: Agri-Biotechnology Research Laboratory, Nippon Paper Industries Co., Ltd. Tokyo, Japan.

ABSTRACT
Eucalyptus species constitutes the most widely planted hardwood trees in temperate and subtropical regions. In this study, we compared the transcript levels of genes involved in lignocellulose formation such as cellulose, hemicellulose and lignin biosynthesis in two selected 3-year old hybrid Eucalyptus (Eucalyptus urophylla × Eucalyptus grandis) genotypes (AM063 and AM380) that have different lignin content. AM063 and AM380 had 20.2 and 35.5% of Klason lignin content and 59.0 and 48.2%, α-cellulose contents, respectively. We investigated the correlation between wood properties and transcript levels of wood formation-related genes using RNA-seq with total RNAs extracted from developing xylem tissues at a breast height. Transcript levels of cell wall construction genes such as cellulose synthase (CesA) and sucrose synthase (SUSY) were almost the same in both genotypes. However, AM063 exhibited higher transcript levels of UDP-glucose pyrophosphorylase and xyloglucan endotransglucoxylase than those in AM380. Most monolignol biosynthesis-related isozyme genes showed higher transcript levels in AM380. These results indicate monolignol biosynthesis-related genes may regulate wood composition in Eucalyptus. Flavonoids contents were also observed at much higher levels in AM380 as a result of the elevated transcript levels of common phenylpropanoid pathway genes, phenylalanine ammonium lyase, cinnamate-4-hydroxylase (C4H) and 4-coumarate-CoA ligase (4CL). Secondary plant cell wall formation is regulated by many transcription factors. We analyzed genes encoding NAC, WRKY, AP2/ERF, and KNOX transcription factors and found higher transcript levels of these genes in AM380. We also observed increased transcription of some MYB and LIM domain transcription factors in AM380 compared to AM063. All these results show that genes related to monolignol biosynthesis may regulate the wood composition and help maintain the ratio of cellulose and lignin contents in Eucalyptus plants.

No MeSH data available.


Workflow: analysis of wood properties and selection of appropriate genotypes. A total of 918 3-year old elite candidate seed-grown trees were analyzed for wood content and distribution of Klason lignin content. Among these, two genotypes, one with the highest and the other with the lowest Klason lignin content were selected. Total RNAs were extracted from developing xylem tissue in each genotype for further analysis.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4829581&req=5

Figure 1: Workflow: analysis of wood properties and selection of appropriate genotypes. A total of 918 3-year old elite candidate seed-grown trees were analyzed for wood content and distribution of Klason lignin content. Among these, two genotypes, one with the highest and the other with the lowest Klason lignin content were selected. Total RNAs were extracted from developing xylem tissue in each genotype for further analysis.

Mentions: In this study, we evaluated wood properties of 918 elite candidate plants using a traditional breeding program, and selected two hybrid Eucalyptus genotypes AM380 and AM063, which exhibited the highest (35.5%) and the lowest (20.2%) Klason lignin content at the progeny evaluation stage (Figure 1). We then compared the transcript profiles in xylem tissues of these two hybrid genotypes. The progeny evaluation was carried out in seed-grown seedlings generated from parent trees that possessed desirable characters such as good growth rate, basic density or kraft pulp yield. In this study, we focused on the correlation between transcript levels of cellulose, hemicellulose and lignin biosynthesis-related genes, and the wood properties. Flavonoid content and the transcript levels of genes involved in flavonoid biosynthesis were also investigated. We found that several transcription factors such as NAC, AP2/ERF, HD, WRKY, MYB, and LIM acted as positive or negative regulators of lignin biosynthesis. Our results strongly suggest that monolignol biosynthesis-related genes may control wood composition.


Transcriptional Profiles of Hybrid Eucalyptus Genotypes with Contrasting Lignin Content Reveal That Monolignol Biosynthesis-related Genes Regulate Wood Composition.

Shinya T, Iwata E, Nakahama K, Fukuda Y, Hayashi K, Nanto K, Rosa AC, Kawaoka A - Front Plant Sci (2016)

Workflow: analysis of wood properties and selection of appropriate genotypes. A total of 918 3-year old elite candidate seed-grown trees were analyzed for wood content and distribution of Klason lignin content. Among these, two genotypes, one with the highest and the other with the lowest Klason lignin content were selected. Total RNAs were extracted from developing xylem tissue in each genotype for further analysis.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4829581&req=5

Figure 1: Workflow: analysis of wood properties and selection of appropriate genotypes. A total of 918 3-year old elite candidate seed-grown trees were analyzed for wood content and distribution of Klason lignin content. Among these, two genotypes, one with the highest and the other with the lowest Klason lignin content were selected. Total RNAs were extracted from developing xylem tissue in each genotype for further analysis.
Mentions: In this study, we evaluated wood properties of 918 elite candidate plants using a traditional breeding program, and selected two hybrid Eucalyptus genotypes AM380 and AM063, which exhibited the highest (35.5%) and the lowest (20.2%) Klason lignin content at the progeny evaluation stage (Figure 1). We then compared the transcript profiles in xylem tissues of these two hybrid genotypes. The progeny evaluation was carried out in seed-grown seedlings generated from parent trees that possessed desirable characters such as good growth rate, basic density or kraft pulp yield. In this study, we focused on the correlation between transcript levels of cellulose, hemicellulose and lignin biosynthesis-related genes, and the wood properties. Flavonoid content and the transcript levels of genes involved in flavonoid biosynthesis were also investigated. We found that several transcription factors such as NAC, AP2/ERF, HD, WRKY, MYB, and LIM acted as positive or negative regulators of lignin biosynthesis. Our results strongly suggest that monolignol biosynthesis-related genes may control wood composition.

Bottom Line: We analyzed genes encoding NAC, WRKY, AP2/ERF, and KNOX transcription factors and found higher transcript levels of these genes in AM380.We also observed increased transcription of some MYB and LIM domain transcription factors in AM380 compared to AM063.All these results show that genes related to monolignol biosynthesis may regulate the wood composition and help maintain the ratio of cellulose and lignin contents in Eucalyptus plants.

View Article: PubMed Central - PubMed

Affiliation: Agri-Biotechnology Research Laboratory, Nippon Paper Industries Co., Ltd. Tokyo, Japan.

ABSTRACT
Eucalyptus species constitutes the most widely planted hardwood trees in temperate and subtropical regions. In this study, we compared the transcript levels of genes involved in lignocellulose formation such as cellulose, hemicellulose and lignin biosynthesis in two selected 3-year old hybrid Eucalyptus (Eucalyptus urophylla × Eucalyptus grandis) genotypes (AM063 and AM380) that have different lignin content. AM063 and AM380 had 20.2 and 35.5% of Klason lignin content and 59.0 and 48.2%, α-cellulose contents, respectively. We investigated the correlation between wood properties and transcript levels of wood formation-related genes using RNA-seq with total RNAs extracted from developing xylem tissues at a breast height. Transcript levels of cell wall construction genes such as cellulose synthase (CesA) and sucrose synthase (SUSY) were almost the same in both genotypes. However, AM063 exhibited higher transcript levels of UDP-glucose pyrophosphorylase and xyloglucan endotransglucoxylase than those in AM380. Most monolignol biosynthesis-related isozyme genes showed higher transcript levels in AM380. These results indicate monolignol biosynthesis-related genes may regulate wood composition in Eucalyptus. Flavonoids contents were also observed at much higher levels in AM380 as a result of the elevated transcript levels of common phenylpropanoid pathway genes, phenylalanine ammonium lyase, cinnamate-4-hydroxylase (C4H) and 4-coumarate-CoA ligase (4CL). Secondary plant cell wall formation is regulated by many transcription factors. We analyzed genes encoding NAC, WRKY, AP2/ERF, and KNOX transcription factors and found higher transcript levels of these genes in AM380. We also observed increased transcription of some MYB and LIM domain transcription factors in AM380 compared to AM063. All these results show that genes related to monolignol biosynthesis may regulate the wood composition and help maintain the ratio of cellulose and lignin contents in Eucalyptus plants.

No MeSH data available.