Table of Contents

Steroidal alkaloids (SAs) are specialized metabolites found in members of the Solanaceae family that provide plants with a chemical barrier against a broad range of pathogens. In this study, the role of GLYCOALKALOID METABOLISM1 (GAME1) in the biosynthesis of tomato SAs was revealed, highlighting the importance of GAME1 in SA glycosylation and in reducing the toxicity of SA metabolites to the plant cell.

This article shows that unprotected telomeres in plant cells are recognized as DNA breaks and elicit a DNA damage signal that is transduced by the ATM and ATR kinases, with differing specificities for eroded and for uncapped telomeres. It finds that both kinases contribute to genomic stability by inducing programmed cell death and elimination of genetically unstable cells.

Steroidal alkaloids (SAs) are specialized metabolites found in members of the Solanaceae family that provide plants with a chemical barrier against a broad range of pathogens. In this study, the role of GLYCOALKALOID METABOLISM1 (GAME1) in the biosynthesis of tomato SAs was revealed, highlighting the importance of GAME1 in SA glycosylation and in reducing the toxicity of SA metabolites to the plant cell.

Steroidal alkaloids (SAs) are specialized metabolites found in members of the Solanaceae family that provide plants with a chemical barrier against a broad range of pathogens. In this study, the role of GLYCOALKALOID METABOLISM1 (GAME1) in the biosynthesis of tomato SAs was revealed, highlighting the importance of GAME1 in SA glycosylation and in reducing the toxicity of SA metabolites to the plant cell.

This study describes a WD-40 repeat–containing gene, POPCORN (PCN), required for embryo development in Arabidopsis thaliana. PCN functions in the auxin pathway and regulates establishment and maintenance of shoot and root meristems during embryonic and postembryonic development.

This study explores the function of two highly conserved isoforms of the Arabidopsis thaliana 26S proteasome subunit RPT2 that participate in proteasome-mediated protein turnover. The data point to a specific role for RPT2 in stem fasciation, male and female gametogenesis, and leaf, root, trichome, and pollen development, along with a common role for RP subunits in histone dynamics and nucleosome assembly.

This work reports on a comprehensive systems biology analysis of maize leaves, concluding that C₄ photosynthesis is established from sink tissue without an intermediate phase of C₃ or C₂ photosynthesis.

This study presents a new modeling approach allowing diverse types of data to be integrated in a coherent molecular regulatory network model. This was used to analyze sepal primordium development and revealed three previously unreported pathways potentially involved in polarity.

This work reports on a comprehensive systems biology analysis of maize leaves, concluding that C₄ photosynthesis is established from sink tissue without an intermediate phase of C₃ or C₂ photosynthesis.

This study describes a WD-40 repeat–containing gene, POPCORN (PCN), required for embryo development in Arabidopsis thaliana. PCN functions in the auxin pathway and regulates establishment and maintenance of shoot and root meristems during embryonic and postembryonic development.

This work reports on a comprehensive systems biology analysis of maize leaves, concluding that C₄ photosynthesis is established from sink tissue without an intermediate phase of C₃ or C₂ photosynthesis.

This article shows that unprotected telomeres in plant cells are recognized as DNA breaks and elicit a DNA damage signal that is transduced by the ATM and ATR kinases, with differing specificities for eroded and for uncapped telomeres. It finds that both kinases contribute to genomic stability by inducing programmed cell death and elimination of genetically unstable cells.

Steroidal alkaloids (SAs) are specialized metabolites found in members of the Solanaceae family that provide plants with a chemical barrier against a broad range of pathogens. In this study, the role of GLYCOALKALOID METABOLISM1 (GAME1) in the biosynthesis of tomato SAs was revealed, highlighting the importance of GAME1 in SA glycosylation and in reducing the toxicity of SA metabolites to the plant cell.

We used maize translocations to identify rough endosperm3 (rgh3) as a locus required in the endosperm to promote embryo development. The rgh3 mutant impairs or delays endosperm cell differentiation and encodes a hypomorphic allele of URP, a core RNA splicing factor. A subset of alternatively spliced transcripts shows differences in splicing patterns in wild-type and rgh3 tissues.

This study explores the function of two highly conserved isoforms of the Arabidopsis thaliana 26S proteasome subunit RPT2 that participate in proteasome-mediated protein turnover. The data point to a specific role for RPT2 in stem fasciation, male and female gametogenesis, and leaf, root, trichome, and pollen development, along with a common role for RP subunits in histone dynamics and nucleosome assembly.

This work examines the chromosomal positional history of all genes in Arabidopsis thaliana through evolutionary time in the rosid superorder, finding that mobile gene families are under different selection pressure than syntenic gene families.

We used maize translocations to identify rough endosperm3 (rgh3) as a locus required in the endosperm to promote embryo development. The rgh3 mutant impairs or delays endosperm cell differentiation and encodes a hypomorphic allele of URP, a core RNA splicing factor. A subset of alternatively spliced transcripts shows differences in splicing patterns in wild-type and rgh3 tissues.

A novel plant-specific inhibitor of anaphase-promoting complex/cyclosome was identified from the gigas cell1 (gig1) mutation, which causes polyploidization of somatic cells due to ectopic endomitosis. This mutation also generated mixed-fate cells with both characters of guard cells and pavement cells, suggesting that GIG1 may have a role in cell fate determination, in addition to its role in proper mitotic progression.

This study identifies cinnamyl alcohol dehydrogenase as the predominant enzyme that catalyzes the final step in S lignin biosynthesis in woody angiosperm xylem and challenges the widely held view that sinapyl alcohol dehydrogenase regulates S lignin biosynthesis in angiosperms.

This massive analysis of rice small RNAs evaluated annotated microRNAs (miRNAs) and identified new miRNAs and miRNAs regulated by environmental stresses. Of particular interest are miRNA family members with distinct sequences and organ-preferential expression; some of these guide differential target cleavage and provide new insight about how an agriculturally significant phenotype may be regulated.

This study demonstrates that Arabidopsis thaliana Lumen Thiol Oxidoreductase1 (LTO1) catalyzes disulfide bond formation in the thylakoid lumen of the chloroplast. Loss of LTO1 function yields an assembly defect in photosystem II, a photosynthetic complex that requires a disulfide bond in a structural subunit localized in the lumen.

The identification and characterization of a glutamyl-tRNA reductase binding protein (GluTRBP) results in a new model for spatial separation of 5-aminolevulinic acid (ALA) formation. GluTRBP-bound GluTR is attached to the thylakoid membrane and synthesizes ALA that is likely directed into the heme-synthesizing pathway.

We used maize translocations to identify rough endosperm3 (rgh3) as a locus required in the endosperm to promote embryo development. The rgh3 mutant impairs or delays endosperm cell differentiation and encodes a hypomorphic allele of URP, a core RNA splicing factor. A subset of alternatively spliced transcripts shows differences in splicing patterns in wild-type and rgh3 tissues.

A novel plant-specific inhibitor of anaphase-promoting complex/cyclosome was identified from the gigas cell1 (gig1) mutation, which causes polyploidization of somatic cells due to ectopic endomitosis. This mutation also generated mixed-fate cells with both characters of guard cells and pavement cells, suggesting that GIG1 may have a role in cell fate determination, in addition to its role in proper mitotic progression.

A novel plant-specific inhibitor of anaphase-promoting complex/cyclosome was identified from the gigas cell1 (gig1) mutation, which causes polyploidization of somatic cells due to ectopic endomitosis. This mutation also generated mixed-fate cells with both characters of guard cells and pavement cells, suggesting that GIG1 may have a role in cell fate determination, in addition to its role in proper mitotic progression.

This study demonstrates that Arabidopsis thaliana Lumen Thiol Oxidoreductase1 (LTO1) catalyzes disulfide bond formation in the thylakoid lumen of the chloroplast. Loss of LTO1 function yields an assembly defect in photosystem II, a photosynthetic complex that requires a disulfide bond in a structural subunit localized in the lumen.

This work identifies ULTRAVIOLET-B-INSENSITIVE4 as a plant-specific inhibitor of the Anaphase-Promoting Complex/Cyclosome E3-ubiquitine ligase. Its activity allows the temporal accumulation of mitotic cyclins during the DNA replication phase, thereby linking DNA replication with mitosis.

This study presents a new modeling approach allowing diverse types of data to be integrated in a coherent molecular regulatory network model. This was used to analyze sepal primordium development and revealed three previously unreported pathways potentially involved in polarity.

This study explores the function of two highly conserved isoforms of the Arabidopsis thaliana 26S proteasome subunit RPT2 that participate in proteasome-mediated protein turnover. The data point to a specific role for RPT2 in stem fasciation, male and female gametogenesis, and leaf, root, trichome, and pollen development, along with a common role for RP subunits in histone dynamics and nucleosome assembly.

This study reveals that the Arabidopsis thaliana microtubule-destabilizing protein MDP25 regulates hypocotyl elongation. The microtubule-destabilizing activity of MDP25 is regulated by calcium, which causes MDP25 to disassociate from the plasma membrane and move into the cytosol. We identified a novel microtubule mechanism that regulates hypocotyl cell elongation in Arabidopsis.

This work uses deep sequencing of RNAs from maize endosperm and embryo to identify 54 maternally expressed genes and 46 paternally expressed genes and then examines genome-wide DNA methylation and gene expression, finding hypomethylation of the maternal allele and endosperm-specific expression for many of the imprinted genes.

This study reveals that the Arabidopsis thaliana microtubule-destabilizing protein MDP25 regulates hypocotyl elongation. The microtubule-destabilizing activity of MDP25 is regulated by calcium, which causes MDP25 to disassociate from the plasma membrane and move into the cytosol. We identified a novel microtubule mechanism that regulates hypocotyl cell elongation in Arabidopsis.

This study explores the function of two highly conserved isoforms of the Arabidopsis thaliana 26S proteasome subunit RPT2 that participate in proteasome-mediated protein turnover. The data point to a specific role for RPT2 in stem fasciation, male and female gametogenesis, and leaf, root, trichome, and pollen development, along with a common role for RP subunits in histone dynamics and nucleosome assembly.

Steroidal alkaloids (SAs) are specialized metabolites found in members of the Solanaceae family that provide plants with a chemical barrier against a broad range of pathogens. In this study, the role of GLYCOALKALOID METABOLISM1 (GAME1) in the biosynthesis of tomato SAs was revealed, highlighting the importance of GAME1 in SA glycosylation and in reducing the toxicity of SA metabolites to the plant cell.

This article identifies plant homologs of the DNA repair protein RAD52. Typically, plants contain two conserved genes, which duplicated early in plant evolution, code for proteins targeted to the nucleus, chloroplast, and mitochondria, and are involved in DNA damage response, homologous recombination, and fertility.

This massive analysis of rice small RNAs evaluated annotated microRNAs (miRNAs) and identified new miRNAs and miRNAs regulated by environmental stresses. Of particular interest are miRNA family members with distinct sequences and organ-preferential expression; some of these guide differential target cleavage and provide new insight about how an agriculturally significant phenotype may be regulated.

This study presents a new modeling approach allowing diverse types of data to be integrated in a coherent molecular regulatory network model. This was used to analyze sepal primordium development and revealed three previously unreported pathways potentially involved in polarity.

Several protocols and methods were developed to study the in vivo structure, ultrastructure, and physiology of sieve tubes. The ultrastructure of sieve tubes differs significantly from what has been shown so far. The impact on phloem function is discussed.

This massive analysis of rice small RNAs evaluated annotated microRNAs (miRNAs) and identified new miRNAs and miRNAs regulated by environmental stresses. Of particular interest are miRNA family members with distinct sequences and organ-preferential expression; some of these guide differential target cleavage and provide new insight about how an agriculturally significant phenotype may be regulated.

The identification and characterization of a glutamyl-tRNA reductase binding protein (GluTRBP) results in a new model for spatial separation of 5-aminolevulinic acid (ALA) formation. GluTRBP-bound GluTR is attached to the thylakoid membrane and synthesizes ALA that is likely directed into the heme-synthesizing pathway.

This work reports on a comprehensive systems biology analysis of maize leaves, concluding that C₄ photosynthesis is established from sink tissue without an intermediate phase of C₃ or C₂ photosynthesis.

We used maize translocations to identify rough endosperm3 (rgh3) as a locus required in the endosperm to promote embryo development. The rgh3 mutant impairs or delays endosperm cell differentiation and encodes a hypomorphic allele of URP, a core RNA splicing factor. A subset of alternatively spliced transcripts shows differences in splicing patterns in wild-type and rgh3 tissues.

This study demonstrates that Arabidopsis thaliana Lumen Thiol Oxidoreductase1 (LTO1) catalyzes disulfide bond formation in the thylakoid lumen of the chloroplast. Loss of LTO1 function yields an assembly defect in photosystem II, a photosynthetic complex that requires a disulfide bond in a structural subunit localized in the lumen.

Steroidal alkaloids (SAs) are specialized metabolites found in members of the Solanaceae family that provide plants with a chemical barrier against a broad range of pathogens. In this study, the role of GLYCOALKALOID METABOLISM1 (GAME1) in the biosynthesis of tomato SAs was revealed, highlighting the importance of GAME1 in SA glycosylation and in reducing the toxicity of SA metabolites to the plant cell.

Steroidal alkaloids (SAs) are specialized metabolites found in members of the Solanaceae family that provide plants with a chemical barrier against a broad range of pathogens. In this study, the role of GLYCOALKALOID METABOLISM1 (GAME1) in the biosynthesis of tomato SAs was revealed, highlighting the importance of GAME1 in SA glycosylation and in reducing the toxicity of SA metabolites to the plant cell.

The identification and characterization of a glutamyl-tRNA reductase binding protein (GluTRBP) results in a new model for spatial separation of 5-aminolevulinic acid (ALA) formation. GluTRBP-bound GluTR is attached to the thylakoid membrane and synthesizes ALA that is likely directed into the heme-synthesizing pathway.

This work reports on a comprehensive systems biology analysis of maize leaves, concluding that C₄ photosynthesis is established from sink tissue without an intermediate phase of C₃ or C₂ photosynthesis.