Arabidopsis GELP7 is plasma membrane-localized acetyl xylan esterase, and its overexpression improves saccharification efficiency.

Abstract Acetyl substitution on the xylan chain is critical for stable interaction with cellulose and other cell wall polymers in the secondary cell wall. Xylan acetylation pattern is governed by Golgi and extracellular localized acetyl xylan esterase (AXE). We investigated the role of Arabidopsis clade Id from the GDSL esterase/lipase or GELP family in polysaccharide deacetylation. The investigation of the AtGELP7 T-DNA mutant line showed a decrease in stem esterase activity and an increase in stem acetyl content. We further generated overexpressor AtGELP7 transgenic lines, and these lines showed a decrease in xylan acetylation in comparison with wild type plants. Therefore, we have named this enzyme as AtAXE1. The subcellular localization studies showed that the AtAXE1 enzyme is secreted out, associated with the plasma membrane and involved in xylan de-esterification post-synthesis. The cellulose digestibility was improved in AtAXE1 overexpressor lines without pre-treatment, after alkali and xylanases pre-treatment. Furthermore, we have also established that the AtGELP7 gene is upregulated in the overexpressor line of AtMYB46, which is a secondary cell wall specific transcription factor. This transcriptional regulation can drive AtGELP7 or AtAXE1 to perform de-esterification of xylan in a tissue-specific manner.

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Organized Cell Wall Biogenesis in Oocystis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050457 ◽

1974 ◽

Vol 32 ◽

pp. 88-89

Author(s):

David Montezinos ◽

R. Malcolm Brown

Keyword(s):

Cell Wall ◽

Plasma Membrane ◽

Secondary Cell Wall ◽

Cell Wall Biogenesis ◽

Complex Process

Patterned arrays of cellulosic microfibrils are found in the secondary cell wall of Oocystis apiculata W. West. Although mechanisms for the biogenesis of the organized cell wall have not yet ben elucidated, roles for the plasma membrane and microtubules in wall production have been suggested. Continuing Study of Oocystis has provided new data on the complex process of organized cell wall biogenesis.

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The dynamic interplay of plasma membrane domains and cortical microtubules in secondary cell wall patterning

Frontiers in Plant Science ◽

10.3389/fpls.2013.00511 ◽

2013 ◽

Vol 4 ◽

Cited By ~ 12

Author(s):

Yoshihisa Oda ◽

Hiroo Fukuda

Keyword(s):

Cell Wall ◽

Plasma Membrane ◽

Secondary Cell Wall ◽

Membrane Domains ◽

Cortical Microtubules ◽

Plasma Membrane Domains ◽

Dynamic Interplay

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Microtubule-associated ROP interactors both delimit and transduce ROP signaling and regulate microtubule dynamics

10.1101/2021.01.08.425872 ◽

2021 ◽

Author(s):

Gil Feiguelman ◽

Xiankui Cui ◽

Hasana Sternberg ◽

Ying Fu ◽

Shaul Yalovsky

Keyword(s):

Cell Wall ◽

Plasma Membrane ◽

Secondary Cell Wall ◽

Root Hairs ◽

Microtubule Dynamics ◽

Wild Type ◽

Multiple Functions ◽

Split Root

Evidence suggests that ICR proteins function as adaptors that mediate ROP signaling. Here, we studied the functions of ICR2 and its homologs ICR5 and ICR3. We showed that ICR2 is a microtubule-associated protein that regulates microtubule dynamics. ICR2 can retrieve activated ROPs from the plasma membrane, and it is recruited to a subset of ROP domains. Secondary cell wall pits in the metaxylem of icr2 and icr5 Arabidopsis single mutants and icr2/icr5 double and icr2/icr5/icr3 triple mutants were denser and larger than those in wild-type Col-0 seedlings, implicating these three ICRs in restriction of ROP function. The icr2 but not the icr5 mutants developed split root hairs further implicating ICR2 in restriction of ROP signaling. Taken together, our results show that ICR2, and likely also ICR5 and ICR3, have multiple functions as ROP effectors and as regulators of microtubule dynamics.

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Overexpression of PtrMYB121 Positively Regulates the Formation of Secondary Cell Wall in Arabidopsis thaliana

International Journal of Molecular Sciences ◽

10.3390/ijms21207734 ◽

2020 ◽

Vol 21 (20) ◽

pp. 7734

Author(s):

Ying Liu ◽

Jiayin Man ◽

Yinghao Wang ◽

Chao Yuan ◽

Yuyu Shi ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Cell Wall ◽

Transcription Factors ◽

Secondary Cell Wall ◽

Tissue Expression ◽

Wild Type ◽

Tissue Expression Analysis ◽

Wide Range ◽

Transgenic Lines ◽

Key Enzyme

MYB transcription factors have a wide range of functions in plant growth, hormone signaling, salt, and drought tolerances. In this study, two homologous transcription factors, PtrMYB55 and PtrMYB121, were isolated and their functions were elucidated. Tissue expression analysis revealed that PtrMYB55 and PtrMYB121 had a similar expression pattern, which had the highest expression in stems. Their expression continuously increased with the growth of poplar, and the expression of PtrMYB121 was significantly upregulated in the process. The full length of PtrMYB121 was 1395 bp, and encoded protein contained 464 amino acids including conserved R2 and R3 MYB domains. We overexpressed PtrMYB121 in Arabidopsis thaliana, and the transgenic lines had the wider xylem as compared with wild-type Arabidopsis. The contents of cellulose and lignin were obviously higher than those in wild-type materials, but there was no significant change in hemicellulose. Quantitative real-time PCR demonstrated that the key enzyme genes regulating the synthesis of lignin and cellulose were significantly upregulated in the transgenic lines. Furthermore, the effector-reporter experiment confirmed that PtrMYB121 bound directly to the promoters of genes relating to the synthesis of lignin and cellulose. These results suggest that PtrMYB121 may positively regulate the formation of secondary cell wall by promoting the synthesis of lignin and cellulose.

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Microanatomy of the Periplasm of Bacillus Licheniformis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065365 ◽

1971 ◽

Vol 29 ◽

pp. 262-263

Author(s):

B.K. Ghosh

Keyword(s):

Cell Wall ◽

Plasma Membrane ◽

Bacillus Licheniformis ◽

External Environment ◽

Permeability Barrier ◽

Periplasmic Space ◽

Modified Technique ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria

Periplasm of bacteria is the space outside the permeability barrier of plasma membrane but enclosed by the cell wall. The contents of this special milieu exterior could be regulated by the plasma membrane from the internal, and by the cell wall from the external environment of the cell. Unlike the gram-negative organism, the presence of this space in gram-positive bacteria is still controversial because it cannot be clearly demonstrated. We have shown the importance of some periplasmic bodies in the secretion of penicillinase from Bacillus licheniformis.In negatively stained specimens prepared by a modified technique (Figs. 1 and 2), periplasmic space (PS) contained two kinds of structures: (i) fibrils (F, 100 Å) running perpendicular to the cell wall from the protoplast and (ii) an array of vesicles of various sizes (V), which seem to have evaginated from the protoplast.

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