Table of Contents

Tomato Protein Kinase 1b (TPK1b) regulates ethylene-mediated defense against pathogens and insect pests. TPK1b RNA interference plants show increased susceptibility to Botrytis infection and insect feeding and are impaired in ethylene responses. These impaired responses correlate with reduced expression of proteinase inhibitor II in response to Botrytis and 1-aminocyclopropane-1-carboxylic acid.

This work shows that auxin regulates late development processes in stamens, coordinating anther dehiscence and pollen maturation and independently triggering filament elongation. In addition, auxin, which is mainly synthesized in the anthers by YUC proteins before the inception of late processes, is perceived by the TIR1 AFB receptors when late processes begin.

Stomata are formed through a series of events: initiation, proliferation, and terminal differentiation. This work identifies the upstream regulator of the cold-induced transcriptome as the core component of stomatal differentiation and suggests a model strikingly similar to cell-type differentiation in animals.

This work describes the isolation and biochemical characterization of the leaf wilting1 (lew1) gene that is responsible for the biosynthesis of dolichols in Arabidopsis. Genetic, molecular, and physiological analyses of the glycosylation defective lew1 mutant show that drought stress signaling converges with endoplasmic reticulum (ER) signaling to regulate ER/UPR (unfolded protein response) and osmotic stress responses.

In this study, the authors show that N-terminal RXLR and dEER motifs, together with flanking sequences, are necessary and sufficient to translocate oomycete effector proteins into host plant cells across the plasma cell membrane. Translocation occurs with purified proteins, indicating that no other pathogen machinery is required.

This work shows that auxin regulates late development processes in stamens, coordinating anther dehiscence and pollen maturation and independently triggering filament elongation. In addition, auxin, which is mainly synthesized in the anthers by YUC proteins before the inception of late processes, is perceived by the TIR1 AFB receptors when late processes begin.

Tomato Protein Kinase 1b (TPK1b) regulates ethylene-mediated defense against pathogens and insect pests. TPK1b RNA interference plants show increased susceptibility to Botrytis infection and insect feeding and are impaired in ethylene responses. These impaired responses correlate with reduced expression of proteinase inhibitor II in response to Botrytis and 1-aminocyclopropane-1-carboxylic acid.

Sphingolipids are essential components of endomembranes and regulators of programmed cell death. This work shows that loss of the C-4 hydroxyl group of sphingolipid long-chain bases (LCBs) in Arabidopsis severely reduces plant growth and increases the content of sphingolipids, primarily with C16 fatty acids. Thus, LCB hydroxylation is important in mediating growth and sphingolipid metabolism.

This work describes the isolation and biochemical characterization of the leaf wilting1 (lew1) gene that is responsible for the biosynthesis of dolichols in Arabidopsis. Genetic, molecular, and physiological analyses of the glycosylation defective lew1 mutant show that drought stress signaling converges with endoplasmic reticulum (ER) signaling to regulate ER/UPR (unfolded protein response) and osmotic stress responses.

Arabidopsis PUB22 and PUB23 encode U-box–containing E3 ubiquitin ligases that are coordinately induced by abiotic stress and interact with a proteasomal subunit. Loss-of-function mutants show increased tolerance to drought stress, while overexpression increases drought sensitivity. This indicates that PUB22 and PUB23 act coordinately to negatively regulate a drought stress signaling pathway.

This work demonstrates the importance of mitochondrial 10-formyl tetrahydrofolate (THF) deformylase and bifunctional 5,10-methylene THF dehydrogenase/5,10-methenyl THF cyclohydrolase in photorespiration. A model showing the involvement of these folate interconversion enzymes in photorespiration is proposed.

The fungus Cladosporium fulvum secretes the effector protein Avr2 during infection of tomato. This work shows that Avr2 interacts with several extracellular Cys proteases in tomato and Arabidopsis. Avr2 expression causes enhanced susceptibility towards several pathogens in both plant species, and, with RNAi-mediated gene silencing in C. fulvum, it is shown that Avr2 is a genuine virulence factor.

Stomata are formed through a series of events: initiation, proliferation, and terminal differentiation. This work identifies the upstream regulator of the cold-induced transcriptome as the core component of stomatal differentiation and suggests a model strikingly similar to cell-type differentiation in animals.

This work describes the isolation and biochemical characterization of the leaf wilting1 (lew1) gene that is responsible for the biosynthesis of dolichols in Arabidopsis. Genetic, molecular, and physiological analyses of the glycosylation defective lew1 mutant show that drought stress signaling converges with endoplasmic reticulum (ER) signaling to regulate ER/UPR (unfolded protein response) and osmotic stress responses.

This work demonstrates the importance of mitochondrial 10-formyl tetrahydrofolate (THF) deformylase and bifunctional 5,10-methylene THF dehydrogenase/5,10-methenyl THF cyclohydrolase in photorespiration. A model showing the involvement of these folate interconversion enzymes in photorespiration is proposed.

Cell separation allows plants to shed entire organs. In Arabidopsis, the IDA gene is required for abscission of floral organs (e.g., petals). A peptide present in IDA and related IDA-LIKE (IDL) proteins is sufficient for IDA function. Genetic evidence suggests that IDA and IDL proteins are ligands that act through membrane-bound receptors to control cell separation events during plant development.

2-acetyl-1-pyrroline (2AP) is a potent flavor component that gives fragrant rice varieties a distinctive flavor. This study shows that a functional Badh2 allele present in nonfragrant rice varieties encodes an enzyme that inhibits 2AP synthesis by exhausting its precursor, whereas null badh2 alleles, found in fragrant rice varieties, result in 2AP accumulation due to a lack of active BADH2 enzyme.

Cell separation allows plants to shed entire organs. In Arabidopsis, the IDA gene is required for abscission of floral organs (e.g., petals). A peptide present in IDA and related IDA-LIKE (IDL) proteins is sufficient for IDA function. Genetic evidence suggests that IDA and IDL proteins are ligands that act through membrane-bound receptors to control cell separation events during plant development.

This work shows that the XopD T3S effector promotes pathogen multiplication in a susceptible host and suppresses the development of chlorosis and necrosis in diseased tissue. Biochemical analysis reveals that XopD possesses DNA binding and transcriptional repressor activity, in addition to SUMO protease activity, indicating that all three activities are required for XopD virulence.

2-acetyl-1-pyrroline (2AP) is a potent flavor component that gives fragrant rice varieties a distinctive flavor. This study shows that a functional Badh2 allele present in nonfragrant rice varieties encodes an enzyme that inhibits 2AP synthesis by exhausting its precursor, whereas null badh2 alleles, found in fragrant rice varieties, result in 2AP accumulation due to a lack of active BADH2 enzyme.

Stomata are formed through a series of events: initiation, proliferation, and terminal differentiation. This work identifies the upstream regulator of the cold-induced transcriptome as the core component of stomatal differentiation and suggests a model strikingly similar to cell-type differentiation in animals.

This work shows that the XopD T3S effector promotes pathogen multiplication in a susceptible host and suppresses the development of chlorosis and necrosis in diseased tissue. Biochemical analysis reveals that XopD possesses DNA binding and transcriptional repressor activity, in addition to SUMO protease activity, indicating that all three activities are required for XopD virulence.

Arabidopsis PUB22 and PUB23 encode U-box–containing E3 ubiquitin ligases that are coordinately induced by abiotic stress and interact with a proteasomal subunit. Loss-of-function mutants show increased tolerance to drought stress, while overexpression increases drought sensitivity. This indicates that PUB22 and PUB23 act coordinately to negatively regulate a drought stress signaling pathway.

Cell separation allows plants to shed entire organs. In Arabidopsis, the IDA gene is required for abscission of floral organs (e.g., petals). A peptide present in IDA and related IDA-LIKE (IDL) proteins is sufficient for IDA function. Genetic evidence suggests that IDA and IDL proteins are ligands that act through membrane-bound receptors to control cell separation events during plant development.

2-acetyl-1-pyrroline (2AP) is a potent flavor component that gives fragrant rice varieties a distinctive flavor. This study shows that a functional Badh2 allele present in nonfragrant rice varieties encodes an enzyme that inhibits 2AP synthesis by exhausting its precursor, whereas null badh2 alleles, found in fragrant rice varieties, result in 2AP accumulation due to a lack of active BADH2 enzyme.

Sphingolipids are essential components of endomembranes and regulators of programmed cell death. This work shows that loss of the C-4 hydroxyl group of sphingolipid long-chain bases (LCBs) in Arabidopsis severely reduces plant growth and increases the content of sphingolipids, primarily with C16 fatty acids. Thus, LCB hydroxylation is important in mediating growth and sphingolipid metabolism.

This work describes the isolation and biochemical characterization of the leaf wilting1 (lew1) gene that is responsible for the biosynthesis of dolichols in Arabidopsis. Genetic, molecular, and physiological analyses of the glycosylation defective lew1 mutant show that drought stress signaling converges with endoplasmic reticulum (ER) signaling to regulate ER/UPR (unfolded protein response) and osmotic stress responses.

Tomato Protein Kinase 1b (TPK1b) regulates ethylene-mediated defense against pathogens and insect pests. TPK1b RNA interference plants show increased susceptibility to Botrytis infection and insect feeding and are impaired in ethylene responses. These impaired responses correlate with reduced expression of proteinase inhibitor II in response to Botrytis and 1-aminocyclopropane-1-carboxylic acid.

This work demonstrates the importance of mitochondrial 10-formyl tetrahydrofolate (THF) deformylase and bifunctional 5,10-methylene THF dehydrogenase/5,10-methenyl THF cyclohydrolase in photorespiration. A model showing the involvement of these folate interconversion enzymes in photorespiration is proposed.

This work describes the isolation and biochemical characterization of the leaf wilting1 (lew1) gene that is responsible for the biosynthesis of dolichols in Arabidopsis. Genetic, molecular, and physiological analyses of the glycosylation defective lew1 mutant show that drought stress signaling converges with endoplasmic reticulum (ER) signaling to regulate ER/UPR (unfolded protein response) and osmotic stress responses.

This study identifies rice plants with mutations in the plastidial phosphorylase (Pho1) gene. The reduced starch content and altered amylopectin structure found in the endosperm of these mutants suggests that Pho1 is a key player in starch biosynthesis in the endosperm of rice.

This work shows that the XopD T3S effector promotes pathogen multiplication in a susceptible host and suppresses the development of chlorosis and necrosis in diseased tissue. Biochemical analysis reveals that XopD possesses DNA binding and transcriptional repressor activity, in addition to SUMO protease activity, indicating that all three activities are required for XopD virulence.

Cell separation allows plants to shed entire organs. In Arabidopsis, the IDA gene is required for abscission of floral organs (e.g., petals). A peptide present in IDA and related IDA-LIKE (IDL) proteins is sufficient for IDA function. Genetic evidence suggests that IDA and IDL proteins are ligands that act through membrane-bound receptors to control cell separation events during plant development.

This study identifies rice plants with mutations in the plastidial phosphorylase (Pho1) gene. The reduced starch content and altered amylopectin structure found in the endosperm of these mutants suggests that Pho1 is a key player in starch biosynthesis in the endosperm of rice.

WRKY transcription factors regulate plant responses to stress. This work describes two WRKY genes from Nicotiana attenuata that regulate jasmonate (JA) accumulation in response to wounding and herbivore-specific elicitors and JA-mediated defenses against herbivores in 3 years of fieldwork with plants silenced in WRKY expression in the plant's native habitat in the Great Basin Desert.

Tomato Protein Kinase 1b (TPK1b) regulates ethylene-mediated defense against pathogens and insect pests. TPK1b RNA interference plants show increased susceptibility to Botrytis infection and insect feeding and are impaired in ethylene responses. These impaired responses correlate with reduced expression of proteinase inhibitor II in response to Botrytis and 1-aminocyclopropane-1-carboxylic acid.

Cell separation allows plants to shed entire organs. In Arabidopsis, the IDA gene is required for abscission of floral organs (e.g., petals). A peptide present in IDA and related IDA-LIKE (IDL) proteins is sufficient for IDA function. Genetic evidence suggests that IDA and IDL proteins are ligands that act through membrane-bound receptors to control cell separation events during plant development.

This work shows that the XopD T3S effector promotes pathogen multiplication in a susceptible host and suppresses the development of chlorosis and necrosis in diseased tissue. Biochemical analysis reveals that XopD possesses DNA binding and transcriptional repressor activity, in addition to SUMO protease activity, indicating that all three activities are required for XopD virulence.

This study identifies rice plants with mutations in the plastidial phosphorylase (Pho1) gene. The reduced starch content and altered amylopectin structure found in the endosperm of these mutants suggests that Pho1 is a key player in starch biosynthesis in the endosperm of rice.

The fungus Cladosporium fulvum secretes the effector protein Avr2 during infection of tomato. This work shows that Avr2 interacts with several extracellular Cys proteases in tomato and Arabidopsis. Avr2 expression causes enhanced susceptibility towards several pathogens in both plant species, and, with RNAi-mediated gene silencing in C. fulvum, it is shown that Avr2 is a genuine virulence factor.

This work describes the isolation and biochemical characterization of the leaf wilting1 (lew1) gene that is responsible for the biosynthesis of dolichols in Arabidopsis. Genetic, molecular, and physiological analyses of the glycosylation defective lew1 mutant show that drought stress signaling converges with endoplasmic reticulum (ER) signaling to regulate ER/UPR (unfolded protein response) and osmotic stress responses.

This study identifies rice plants with mutations in the plastidial phosphorylase (Pho1) gene. The reduced starch content and altered amylopectin structure found in the endosperm of these mutants suggests that Pho1 is a key player in starch biosynthesis in the endosperm of rice.

This work describes the isolation and biochemical characterization of the leaf wilting1 (lew1) gene that is responsible for the biosynthesis of dolichols in Arabidopsis. Genetic, molecular, and physiological analyses of the glycosylation defective lew1 mutant show that drought stress signaling converges with endoplasmic reticulum (ER) signaling to regulate ER/UPR (unfolded protein response) and osmotic stress responses.

2-acetyl-1-pyrroline (2AP) is a potent flavor component that gives fragrant rice varieties a distinctive flavor. This study shows that a functional Badh2 allele present in nonfragrant rice varieties encodes an enzyme that inhibits 2AP synthesis by exhausting its precursor, whereas null badh2 alleles, found in fragrant rice varieties, result in 2AP accumulation due to a lack of active BADH2 enzyme.