Expansins as Agents in Hormone Action

Choe, Hyung T.; Cosgrove, Daniel J.

doi:10.1007/978-1-4020-2686-7_13

Cited by 19 publications

(20 citation statements)

References 42 publications

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“…Transgenic and genetic studies have demonstrated that expansins play roles in cell enlargement, fruit softening, abscission, germination, pathogenesis and pollen tube growth (reviewed in Cho and Cosgrove, 2004;Choi et al, 2006;Cosgrove, 2000). Thus far, we have only had circumstantial evidence to suggest that expansins might be involved in root hair growth.…”

Section: Resultsmentioning

confidence: 99%

Root Hair-Specific EXPANSIN A7 Is Required for Root Hair Elongation in Arabidopsis

Lin

Choi

Cho

2011

Molecules and Cells

109

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Expansins are non-hydrolytic cell wall-loosening proteins that are involved in the cell wall modifications that underlie many plant developmental processes. Root hair growth requires the accumulation of cell wall materials and dynamic cell wall modification at the tip region. Although several lines of indirect evidence support the idea that expansin-mediated wall modification occurs during root hair growth, the involvement of these proteins remains to be demonstrated in vivo. In this study, we used RNA interference (RNAi) to examine the biological function of Arabidopsis thaliana EXPANSIN A7 (AtEXPA7), which is expressed specifically in the root hair cell. The root hairspecific AtEXPA7 promoter was used to drive RNAi expression, which targeted two independent regions in the AtEXPA7 transcript. Quantitative reverse transcriptase-PCR analyses were used to examine AtEXPA7 transcript levels. In four independent RNAi transformant lines, RNAi expression reduced AtEXPA7 transcript levels by 25-58% compared to controls. Accordingly, the root hairs of RNAi transformant lines were 25-48% shorter than control plants and exhibited a broader range of lengths than the controls. Our results provide in vivo evidence that expansins are required for root hair tip growth.

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Section: Resultsmentioning

confidence: 99%

Root Hair-Specific EXPANSIN A7 Is Required for Root Hair Elongation in Arabidopsis

Lin

Choi

Cho

2011

Molecules and Cells

109

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“…17 Cell wall modifying proteins such as expansins and XTHs comprise large gene families [90][91][92] and individual members are known to be regulated by the hormones GA, ethylene, auxin and BR. [93][94][95][96] Auxin plays a role in the acidification of the apoplast, where auxin can lower the apoplastic pH within minutes. 97 This rapid acidification probably sets the optimal pH for cell wall modifying proteins such as expansins 98 and XTHs.…”

Section: Discussionmentioning

confidence: 99%

Physiological regulation and functional significance of shade avoidance responses to neighbors

Keuskamp

Sasidharan

Pierik

2010

Plant Signaling & Behavior

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Besides being a source of energy, light is also a source of information that plants can respond to. Most plants are able to react to the direction, intensity, composition and duration of light. These light components regulate such features as seed germination, photomorphogenesis, flowering time and the SAS. [10][11][12] The SAS encompasses various phenotypic traits (Fig. 1), including elongation of internodes, petioles and hypocotyls, apical dominance, early flowering and upward leaf movement (hyponasty).

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“…Recent examples include the diverse expression of EXPB genes in soybean, particularly during Rhizobium infection and mycorrhiza associations [53], the expression of expansin genes in the wheat peduncle with modulation by Rht alleles for dwarfism, the involvement of multiple expansin genes in Arabidopsis leaf growth [54], and the complex regulation of expansin gene expression in grape during berry ripening and during phylloxera-induced gall formation [17,55]. Building on earlier studies (reviewed in [56]), recent work has also documented expression of specific expansin genes in response to various hormones [57–60]. Wherever cells are growing or modifying their cell walls, one or more expansin genes are usually involved.…”

Section: Developmental Expressionmentioning

confidence: 99%

Plant expansins: diversity and interactions with plant cell walls

Cosgrove

2015

Current Opinion in Plant Biology

405

370

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Expansins were discovered two decades ago as cell wall proteins that mediate acid-induced growth by catalyzing loosening of plant cell walls without lysis of wall polymers. In the interim our understanding of expansins has gotten more complex through bioinformatic analysis of expansin distribution and evolution, as well as through expression analysis, dissection of the upstream transcription factors regulating expression, and identification of additional classes of expansin by sequence and structural similarities. Molecular analyses of expansins from bacteria have identified residues essential for wall loosening activity and clarified the bifunctional nature of expansin binding to complex cell walls. Transgenic modulation of expansin expression modifies growth and stress physiology of plants, but not always in predictable and even understandable ways.

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Expansins as Agents in Hormone Action

Cited by 19 publications

References 42 publications

Root Hair-Specific EXPANSIN A7 Is Required for Root Hair Elongation in Arabidopsis

Root Hair-Specific EXPANSIN A7 Is Required for Root Hair Elongation in Arabidopsis

Physiological regulation and functional significance of shade avoidance responses to neighbors

Plant expansins: diversity and interactions with plant cell walls

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