Table of Contents

This works shows that sunflower seed dormancy alleviation during dry after-ripening is associated with oxidation of a specific subset of 24 seed stored mRNAs. Oxidized transcripts are not translated into their corresponding proteins during subsequent seed imbibition, which may govern cell signaling leading to germination.

The maize gene opaque5 encodes a monogalactosyldiacylglycerol synthase. Mutant analysis reveals that galactolipids with five double bonds are needed for thylakoid membrane function and cannot be substituted by the prevalent species with six double bonds. Galactolipid reduction results in altered starch granules, indicating a connection between amyloplast membranes and starch biosynthesis.

This study shows that Arabidopsis has two classes of ceramide synthases discriminating acyl chain length and also that very-long-acyl-chain sphingolipids are required for polar auxin transport in particular during lateral root emergence. These lipids define a secretory pathway with specific endomembrane compartments and polar auxin transport protein cargoes.

This study shows that a WUSCHEL-like gene, STENOFOLIA (STF), is required for blade outgrowth, and its deletion accounts for the classical bladeless lam1 phenotype of tobacco (Nicotiana sylvestris). STF confers morphogenetic competence to leaf primordial margins and coordinates auxin/cytokinin homeostasis and hormone crosstalk with sugar metabolism, integrating metabolic and developmental signals.

This work demonstrates that glutathione is the sulfur donor for the biosynthesis of glucosinolates, plant compounds that play important roles in agriculture, ecology, and human health. Furthermore, it identifies the enzymes that act immediately downstream of the sulfur donation step (γ-glutamylpeptidases), thereby assigning a previously unknown in planta function to this family of enzymes.

We carried out a comparative transcriptome analysis in leaves of five closely related C₃, C₄, and C₃-C₄ intermediate Flaveria species to gain insight into the extent to which gene expression patterns were altered in the evolutionary progression from C₃ to C₄. The comparative analysis indicates that C₄ evolution affected far more biological functions than only photosynthesis.

This study presents a broad functional survey of a large sample of candidate RXLR effectors in the oomycete pathogen of soybean (Phytophthora sojae). Suppression of plant defense, transcription patterns, and polymorphisms were assayed. Essential effectors and effector subsets with distinct expression patterns and defense suppression activities were identified.

This study determines the subunit stoichiometry of the tetradecameric caseinolytic protease (Clp) protease, the most abundant soluble protease in plant plastids. Using tagged Clp subunits and stable isotope-labeled peptides for mass spectrometry-based quantification, this analysis provides information that is critical for understanding the interaction of Clp protease with Clp chaperones and substrate delivery systems.

This work investigates coordinated actin filament and microtubule activities. It shows that actin filaments and microtubules interact dynamically and that actin filaments depend on microtubules to recover following drug-induced depolymerization events.

This study presents a broad functional survey of a large sample of candidate RXLR effectors in the oomycete pathogen of soybean (Phytophthora sojae). Suppression of plant defense, transcription patterns, and polymorphisms were assayed. Essential effectors and effector subsets with distinct expression patterns and defense suppression activities were identified.

This work investigates coordinated actin filament and microtubule activities. It shows that actin filaments and microtubules interact dynamically and that actin filaments depend on microtubules to recover following drug-induced depolymerization events.

Botrytis cinerea is a necrotrophic pathogen that causes grey mould disease in a broad host range, including tomato, grapes, potato, and strawberry. Here, we report that B. cinerea secretes a virulence factor that hijacks the plant’s own crosstalk network to promote disease development.

Botrytis cinerea is a necrotrophic pathogen that causes grey mould disease in a broad host range, including tomato, grapes, potato, and strawberry. Here, we report that B. cinerea secretes a virulence factor that hijacks the plant’s own crosstalk network to promote disease development.

This study presents a broad functional survey of a large sample of candidate RXLR effectors in the oomycete pathogen of soybean (Phytophthora sojae). Suppression of plant defense, transcription patterns, and polymorphisms were assayed. Essential effectors and effector subsets with distinct expression patterns and defense suppression activities were identified.

A rice male-sterile mutant, defective pollen wall (dpw), which has defective anthers and pollen grains, is isolated and characterized. DPW is found to encode a fatty acyl carrier protein reductase that is active during the synthesis of the anther cuticle and pollen sporopollenin.

This study shows that Arabidopsis has two classes of ceramide synthases discriminating acyl chain length and also that very-long-acyl-chain sphingolipids are required for polar auxin transport in particular during lateral root emergence. These lipids define a secretory pathway with specific endomembrane compartments and polar auxin transport protein cargoes.

Developmental processes like seed germination are characterized by massive transcriptome changes. This study compares seed transcriptome data sets of different Brassicaceae to identify stable expressed reference genes for cross-species quantitative RT-PCR normalization. A workflow is presented for improving RNA quality, quantitative RT-PCR performance, and normalization when analyzing expression changes across species.

This study presents a broad functional survey of a large sample of candidate RXLR effectors in the oomycete pathogen of soybean (Phytophthora sojae). Suppression of plant defense, transcription patterns, and polymorphisms were assayed. Essential effectors and effector subsets with distinct expression patterns and defense suppression activities were identified.

This study presents a broad functional survey of a large sample of candidate RXLR effectors in the oomycete pathogen of soybean (Phytophthora sojae). Suppression of plant defense, transcription patterns, and polymorphisms were assayed. Essential effectors and effector subsets with distinct expression patterns and defense suppression activities were identified.

The dehydrin family of proteins is upregulated in response to desiccation and cold stress and is thought to protect the plant by stabilizing the plasma membrane. This study characterizes the interaction between a typical dehydrin (Lti30) and lipid membranes.

This study shows that Arabidopsis has two classes of ceramide synthases discriminating acyl chain length and also that very-long-acyl-chain sphingolipids are required for polar auxin transport in particular during lateral root emergence. These lipids define a secretory pathway with specific endomembrane compartments and polar auxin transport protein cargoes.

Little is known about the role the cytoskeleton plays in signaling with regard to the outcome of plant–microbe interactions. This work describes a regulator of cytoskeleton organization and of disease susceptibility shuttling between microtubules and the monomeric G-protein RACB at the cell periphery.

This work shows that a mutation of the PIN1 ortholog in Medicago truncatula, SLM1, caused multiple terminal leaflets and a reduction of lateral leaflets. Characterization of the mutant reveals that the terminal leaflet primordium in M. truncatula has a unique developmental mechanism and the elaboration of compound leaves is context dependent and tightly correlated with the auxin/SLM1 module.

Little is known about the role the cytoskeleton plays in signaling with regard to the outcome of plant–microbe interactions. This work describes a regulator of cytoskeleton organization and of disease susceptibility shuttling between microtubules and the monomeric G-protein RACB at the cell periphery.

This work presents physiological, cell biological, and developmental data that establish that gibberellins (GA) is required for proper polar auxin transport in Arabidopsis thaliana. It shows that the GA pathway interacts with PIN protein-dependent auxin transport and development, suggesting that at least some of the growth defects of GA biosynthesis and signaling mutants are a result of altered auxin transport.

Rice pps is a heterochronic mutant that shows a prolonged juvenile phase by repressing GA biosynthetic genes and altering expression patterns of microRNA genes but is early flowering. Positional cloning revealed that PPS is the ortholog of Arabidopsis COP1. Although PPS has a role in photomorphogenesis as COP1 does, PPS has additional roles in vegetative phase change and flowering time regulation.

Functional analyses of cytokinin (CK)-deficient plants provide direct evidence that CKs negatively regulate plant response to drought and salt stresses. CK-deficient plants exhibited a strong stress-tolerant phenotype associated with abscisic acid (ABA) hypersensitivity. This study suggests that mutual regulation mechanisms between CK and ABA affect the plant’s adaptation to stressors and plant growth and development.

This work investigates coordinated actin filament and microtubule activities. It shows that actin filaments and microtubules interact dynamically and that actin filaments depend on microtubules to recover following drug-induced depolymerization events.

This study determines the subunit stoichiometry of the tetradecameric caseinolytic protease (Clp) protease, the most abundant soluble protease in plant plastids. Using tagged Clp subunits and stable isotope-labeled peptides for mass spectrometry-based quantification, this analysis provides information that is critical for understanding the interaction of Clp protease with Clp chaperones and substrate delivery systems.

This work describes the development of a robust and quantitative system for elucidating the sequences and trans-acting factors required for de novo telomere formation in Arabidopsis thaliana. We determine that genetic redundancy and the nonhomologous end-joining factors Ku and Lig4 facilitate higher levels of de novo telomere formation.

This works shows that sunflower seed dormancy alleviation during dry after-ripening is associated with oxidation of a specific subset of 24 seed stored mRNAs. Oxidized transcripts are not translated into their corresponding proteins during subsequent seed imbibition, which may govern cell signaling leading to germination.

Developmental processes like seed germination are characterized by massive transcriptome changes. This study compares seed transcriptome data sets of different Brassicaceae to identify stable expressed reference genes for cross-species quantitative RT-PCR normalization. A workflow is presented for improving RNA quality, quantitative RT-PCR performance, and normalization when analyzing expression changes across species.

This work examines downstream targets of MYB80 and shows that an aspartic protease regulated by MYB80 is involved in the timing of programmed cell death of the tapetum in the Arabidopsis anther.

This study shows that a WUSCHEL-like gene, STENOFOLIA (STF), is required for blade outgrowth, and its deletion accounts for the classical bladeless lam1 phenotype of tobacco (Nicotiana sylvestris). STF confers morphogenetic competence to leaf primordial margins and coordinates auxin/cytokinin homeostasis and hormone crosstalk with sugar metabolism, integrating metabolic and developmental signals.

This work investigates coordinated actin filament and microtubule activities. It shows that actin filaments and microtubules interact dynamically and that actin filaments depend on microtubules to recover following drug-induced depolymerization events.

A rice male-sterile mutant, defective pollen wall (dpw), which has defective anthers and pollen grains, is isolated and characterized. DPW is found to encode a fatty acyl carrier protein reductase that is active during the synthesis of the anther cuticle and pollen sporopollenin.

This study shows that a WUSCHEL-like gene, STENOFOLIA (STF), is required for blade outgrowth, and its deletion accounts for the classical bladeless lam1 phenotype of tobacco (Nicotiana sylvestris). STF confers morphogenetic competence to leaf primordial margins and coordinates auxin/cytokinin homeostasis and hormone crosstalk with sugar metabolism, integrating metabolic and developmental signals.

This study shows the identification of a plant-specific actin binding protein, STOMATAL CLOSURE-RELATED ACTIN BINDING PROTEIN1, which associates with and stabilizes microfilaments, and regulates microfilament reorganization during stomatal closure in response to drought stress.

This study shows that Arabidopsis has two classes of ceramide synthases discriminating acyl chain length and also that very-long-acyl-chain sphingolipids are required for polar auxin transport in particular during lateral root emergence. These lipids define a secretory pathway with specific endomembrane compartments and polar auxin transport protein cargoes.

This study demonstrates a role for Rho family GTPases (ROPs) in asymmetric cell division in maize. Functional and localization studies together with analysis of physical interactions demonstrate that ROPs function cooperatively with the receptor-like protein PAN1 to promote the premitotic polarization of subsidiary mother cells during stomatal complex development.

This work demonstrates that glutathione is the sulfur donor for the biosynthesis of glucosinolates, plant compounds that play important roles in agriculture, ecology, and human health. Furthermore, it identifies the enzymes that act immediately downstream of the sulfur donation step (γ-glutamylpeptidases), thereby assigning a previously unknown in planta function to this family of enzymes.

Gloeobacter violaceus, the most primordial of known organisms performing oxygenic photosynthesis, evolved before the evolutionary appearance of thylakoid membranes. This study demonstrates the presence of bioenergetic domains in its cytoplasmic membrane. The formation of these membrane domains might constitute evolutionary precursors of the thylakoid membrane.

This work describes the development of a robust and quantitative system for elucidating the sequences and trans-acting factors required for de novo telomere formation in Arabidopsis thaliana. We determine that genetic redundancy and the nonhomologous end-joining factors Ku and Lig4 facilitate higher levels of de novo telomere formation.

This work examines downstream targets of MYB80 and shows that an aspartic protease regulated by MYB80 is involved in the timing of programmed cell death of the tapetum in the Arabidopsis anther.

This work investigates coordinated actin filament and microtubule activities. It shows that actin filaments and microtubules interact dynamically and that actin filaments depend on microtubules to recover following drug-induced depolymerization events.

This study shows that a WUSCHEL-like gene, STENOFOLIA (STF), is required for blade outgrowth, and its deletion accounts for the classical bladeless lam1 phenotype of tobacco (Nicotiana sylvestris). STF confers morphogenetic competence to leaf primordial margins and coordinates auxin/cytokinin homeostasis and hormone crosstalk with sugar metabolism, integrating metabolic and developmental signals.

This study shows the identification of a plant-specific actin binding protein, STOMATAL CLOSURE-RELATED ACTIN BINDING PROTEIN1, which associates with and stabilizes microfilaments, and regulates microfilament reorganization during stomatal closure in response to drought stress.