Plant Biology

Structural basis for the absence of low-energy chlorophylls in a photosystem I trimer from Gloeobacter violaceus

1. Koji Kato
2. Tasuku Hamaguchi
3. Ryo Nagao
4. Keisuke Kawakami
5. Yoshifumi Ueno
6. Takehiro Suzuki
7. Hiroko Uchida
8. Akio Murakami
9. Yoshiki Nakajima
10. Makio Yokono
11. Seiji Akimoto
12. Naoshi Dohmae
13. Koji Yonekura
14. Jian-Ren Shen

• Curated by eLife

  Evaluation Summary:

  This work reports the structure of the photosystem I of Gloeobacter, a cyanobacterium that does not contain low energy absorbing chlorophylls, the so-called red forms. By comparing this structure to those of other cyanobacteria that contain red forms, the authors aim to identify the chlorophylls responsible for low-energy absorption in PSI. Their second aim is to understand the role of the red forms. The topic is interesting, the structural data are very good, but the conclusions regarding the role of the red forms are not supported by data.

  (This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #1 agreed to share their name with the authors.)

Reviewed by eLife

The Arabidopsis SAC9 enzyme is enriched in a cortical population of early endosomes and restricts PI(4,5)P2 at the plasma membrane

1. Alexis Lebecq
2. Mehdi Doumane
3. Aurelie Fangain
4. Vincent Bayle
5. Jia Xuan Leong
6. Frédérique Rozier
7. Maria del Marques-Bueno
8. Laia Armengot
9. Romain Boisseau
10. Mathilde Laetitia Simon
11. Mirita Franz-Wachtel
12. Boris Macek
13. Suayib Üstün
14. Yvon Jaillais
15. Marie-Cécile Caillaud

• Curated by eLife

  Evaluation Summary:

  Phosphoinositide phosphates (PIPs) are lipids that can convey distinct identities to different cellular membranes via different phosphorylation patterns. Here, Doumane and co-authors document the effects of the previously-characterized sac9 mutant, affecting a putative PIP-5-phosphatase in Arabidopsis, on PIP localization and endocytic trafficking. This work confirms that disrupting PI(4,5)P2 localization can affect endocytic trafficking in plants and will be of interest to the plant and cell biology research fields.

  (This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #2 and Reviewer #3 agreed to share their name with the authors.)

Reviewed by eLife

Functional diversification gave rise to allelic specialization in a rice NLR immune receptor pair

1. Juan Carlos De la Concepcion
2. Javier Vega Benjumea
3. Aleksandra Bialas
4. Ryohei Terauchi
5. Sophien Kamoun
6. Mark J Banfield

• Curated by eLife

  Evaluation Summary:

  De la Concepcion and colleagues investigated the mode of co-evolution of plant immune receptor pair that functions as a unit to detect pathogen invasion and turn on immunity. The study shows that an allelic mismatch of a receptor paired from rice can cause autoimmunity in the absence of pathogen effectors, and this can be traced to polymorphisms that arose fairly recently. Overall the study provides insights into the co-evolution of paired receptors and supports that the paired receptors have co-evolved to prevent premature inactivation and enable strong activation in response to matching effectors.

  (This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #1 and Reviewer #2 agreed to share their names with the authors.)

Reviewed by eLife

A coupled mechano-biochemical model for cell polarity guided anisotropic root growth

1. Marco Marconi
2. Marcal Gallemi
3. Eva Benkova
4. Krzysztof Wabnik

• Curated by eLife

  Evaluation Summary:

  The paper describes the development of a mechano-chemical model for plant root development. As such, it presents a significant advance relative to other root models that have focussed predominantly on either the mechanical or auxin patterning aspects of root development, as evidenced by the potential of the model to reproduce a series of hormonal and mechanical perturbation experiments. The current conclusion that a set of minimal principles for self-organized root tip patterning is revealed must be moderated, as patterning inputs are essential to produce the reported observations.

  (This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #3 agreed to share their name with the authors.)

Reviewed by eLife

Members of the ELMOD protein family specify formation of distinct aperture domains on the Arabidopsis pollen surface

1. Yuan Zhou
2. Prativa Amom
3. Sarah H Reeder
4. Byung Ha Lee
5. Adam Helton
6. Anna A Dobritsa

• Curated by eLife

  Evaluation Summary:

  How pollen apertures are formed is not well understood. By studying Arabidopsis mutants producing pollen with aberrant aperture numbers, the authors identify proteins from the ELMOD protein family as important regulators for aperture formation. They use genetics, transgenic constructs, and site-directed mutagenesis to pinpoint important residues for protein function in this process, and show that changes in expression levels of one protein can have dramatic effects on patterning. This paper will interest scientists interested in cell polarity, patterning, and evolution of diverse morphologies. This is also the first study of the ELMOD protein family, whose potential GTPase activating activities have not yet been investigated in plants.

  (This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #1 and Reviewer #2 agreed to share their names with the authors.)

Reviewed by eLife

A novel bivalent chromatin associates with rapid induction of camalexin biosynthesis genes in response to a pathogen signal in Arabidopsis

1. Kangmei Zhao
2. Deze Kong
3. Benjamin Jin
4. Christina D Smolke
5. Seung Yon Rhee

• Curated by eLife

  Evaluation Summary:

  This study proposes the identification of "bivalent chromatin" in genes associated with the biosynthesis of secondary metabolites in Arabidopsis and describes an investigation into the role of chromatin states in the regulation of the major Arabidopsis phytoalexin. Perturbation of either H3K27me3 or H3K18ac levels using mutants were used to show that there were effects on the expression of these metabolic genes. It has previously been shown that H3K27me3 and H3K18ac colocalize in the Arabidopsis genome and that genes targeted by PRC2/H3K27me3 in Arabidopsis are enriched for genes that respond to the environment and/or developmental cues. Therefore, the reported changes to the regulation of these genes in defective mutants are as expected, although the finding of this study will still be of interest to those working on pathogen-induced changes to plant metabolism.

  (This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. The reviewers remained anonymous to the authors.)

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The induction of pyrenoid synthesis by hyperoxia and its implications for the natural diversity of photosynthetic responses in Chlamydomonas

1. Peter Neofotis
2. Joshua Temple
3. Oliver L Tessmer
4. Jacob Bibik
5. Nicole Norris
6. Eric Pollner
7. Ben Lucker
8. Sarathi M Weraduwage
9. Alecia Withrow
10. Barbara Sears
11. Greg Mogos
12. Melinda Frame
13. David Hall
14. Joseph Weissman
15. David M Kramer

• Curated by eLife

  Evaluation Summary:

  Many algae, such as Chlamydomonas, form a pyrenoid under certain conditions to enable high photosynthetic rates during inorganic carbon limitation. The data presented here support that hydrogen peroxide, a common by-product of hyperoxia and CO2 limitation, induces pyrenoid formation in Chlamydomonas, even when CO2 levels are high. Although the underlying genetic mechanisms remain unresolved, these observations offer an exciting starting point to dissect the molecular components that drive pyrenoid formation. Therefore, this paper is of interest to a broad audience of scientists working in the areas of photosynthesis, synthetic biology of agriculture, and algal biotechnology.

  (This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. The reviewers remained anonymous to the authors.)

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Expression of a CO2-permeable aquaporin enhances mesophyll conductance in the C4 species Setaria viridis

1. Maria Ermakova
2. Hannah Osborn
3. Michael Groszmann
4. Soumi Bala
5. Andrew Bowerman
6. Samantha McGaughey
7. Caitlin Byrt
8. Hugo Alonso-cantabrana
9. Steve Tyerman
10. Robert T Furbank
11. Robert E Sharwood
12. Susanne von Caemmerer

• Curated by eLife

  Evaluation Summary:

  The conductance of CO2 into the chloroplast from the intercellular airspace is a key limitation to rates of net photosynthesis. Despite its importance, past work has been contradictory in what does and does not affect this mesophyll conductance. This paper takes a unique and multi-pronged approach to resolving the mechanisms of mesophyll conductance and proposing a transgenic approach for increasing it in C4 plants.

  (This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #2 agreed to share their name with the authors.)

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Control of Arabidopsis shoot stem cell homeostasis by two antagonistic CLE peptide signalling pathways

1. Jenia Schlegel
2. Gregoire Denay
3. Rene Wink
4. Karine Gustavo Pinto
5. Yvonne Stahl
6. Julia Schmid
7. Patrick Blümke
8. Rüdiger GW Simon

• Curated by eLife

  Evaluation Summary:

  Vertical patterning of the shoot meristem is regulated by a well-characterized feedback loop involving the CLAVATA3 peptide, the CLAVATA1 receptor-like kinase and the WUSCHEL transcription factor. Cell loss from the Peripheral Zone of the meristem, due to production of lateral organs, requires a compensatory size increase of the stem cell domain, i.e. there is a need to understand how stem cell activities in the Central Zone and Organizing Center are coordinated to regulate organ initiation and cell differentiation in the Peripheral Zone. The authors identify a new signaling pathway to control shoot meristem function in Arabidopsis, suggesting that the peptide CLE40 and the receptor kinase-like protein BAM1 act from the Peripheral Zone to stimulate stem cell fate via WUSCHEL expression, and antagonistically to the CLV pathway. The model is novel and exciting and will be of interest to plant scientists as well as those interested in developmental patterning. Some additional evidence is required to fully sufficient to support all claims in the manuscript.

  (This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #1 agreed to share their name with the authors.)

Reviewed by eLife

The structure and flexibility analysis of the Arabidopsis synaptotagmin 1 reveal the basis of its regulation at membrane contact sites

1. Juan L Benavente
2. Dritan Siliqi
3. Lourdes Infantes
4. Laura Lagartera
5. Alberto Mills
6. Federico Gago
7. Noemí Ruiz-López
8. Miguel A Botella
9. María J Sánchez-Barrena
10. Armando Albert

Reviewed by Review Commons