Table of Contents

This work describes a Chlamydomonas mutant (pgrl1) isolated from a screen designed to identify new photosynthetic regulatory mechanisms. It provides evidence that in the wild type, photosynthetic electron supply to hydrogenase is severely limited by the proton gradient generated by cyclic electron flow, opening new perspective towards optimizing hydrogen production by microalgae.

This study examines the lignin biosynthesis pathway in the lycophyte Selaginella moellendorffii. An O-methyltransferase gene was found clustered with the gene encoding a phenylpropanoid meta-hydroxylase known to catalyze the formation of syringyl lignin subunits. The O-methyltransferase is shown to function in the same enzymatic pathway as the phenylpropanoid meta-hydroxylase.

This work presents the cucumber mitochondrial genome sequence. Its extremely large size reflects the proliferation of dispersed repeats, large introns, and an abundance of chloroplast and nuclear DNA. The genome has an unusual multichromosomal structure, and computational analyses reveal a large number of recombinationally active repeats.

Analysis of a series of mutants lacking each of the three isoforms of the Lhcb4 light-harvesting complex in Arabidopsis showed that this complex plays an important role in the macro-organization and photoprotection of photosystem II.

This work identified two different Arabidopsis mutants that have reduced susceptibility to an infectious biotrophic pathogen due to overaccumulation of the amino acid Thr. This is detrimental for the host plant and the infecting pathogen but does not affect disease caused by some other pathogen species. Therefore, the host metabolic state can influence disease in quite a specific manner.

The slow vacuolar channel is the dominant cation channel of the vacuolar membrane and is regulated by cytosolic as well as vacuolar calcium. Here, the vacuolar calcium binding site is characterized at the molecular level, adding to our understanding of calcium signaling in the extracytosolic space.

Analysis of a series of mutants lacking each of the three isoforms of the Lhcb4 light-harvesting complex in Arabidopsis showed that this complex plays an important role in the macro-organization and photoprotection of photosystem II.

This work examines the role of the citrate transporter FRD3 in iron homeostasis during plant development, finding key roles in pollen and embryo development, and in leaf, in addition to its known role in roots and in the apoplastic transport of iron.

Analysis of a series of mutants lacking each of the three isoforms of the Lhcb4 light-harvesting complex in Arabidopsis showed that this complex plays an important role in the macro-organization and photoprotection of photosystem II.

This work analyzed genome-wide binding sites of a transposase-derived transcription factor, FHY3, using a chromatin immunoprecipitation–based sequencing approach and identified a role for FHY3 in controlling chloroplast development by directly activating the expression of ARC5, a key gene involved in chloroplast division.

This work describes a Chlamydomonas mutant (pgrl1) isolated from a screen designed to identify new photosynthetic regulatory mechanisms. It provides evidence that in the wild type, photosynthetic electron supply to hydrogenase is severely limited by the proton gradient generated by cyclic electron flow, opening new perspective towards optimizing hydrogen production by microalgae.

This work describes a Chlamydomonas mutant (pgrl1) isolated from a screen designed to identify new photosynthetic regulatory mechanisms. It provides evidence that in the wild type, photosynthetic electron supply to hydrogenase is severely limited by the proton gradient generated by cyclic electron flow, opening new perspective towards optimizing hydrogen production by microalgae.

Ectopic expression of a MYB transcription factor, ODO1, in tomato fruit altered Phe and phenylpropanoid metabolism, as shown by metabolic profiling and flux analysis. This disruption permitted identification of a set of coregulated genes, including prephenate aminotransferase, which converts prephenate to arogenate. The results establish a fruit arogenate pathway for Phe synthesis.

Analysis of a series of mutants lacking each of the three isoforms of the Lhcb4 light-harvesting complex in Arabidopsis showed that this complex plays an important role in the macro-organization and photoprotection of photosystem II.

This work analyzed genome-wide binding sites of a transposase-derived transcription factor, FHY3, using a chromatin immunoprecipitation–based sequencing approach and identified a role for FHY3 in controlling chloroplast development by directly activating the expression of ARC5, a key gene involved in chloroplast division.

Ectopic expression of a MYB transcription factor, ODO1, in tomato fruit altered Phe and phenylpropanoid metabolism, as shown by metabolic profiling and flux analysis. This disruption permitted identification of a set of coregulated genes, including prephenate aminotransferase, which converts prephenate to arogenate. The results establish a fruit arogenate pathway for Phe synthesis.

This work localizes a functional LYK3-GFP protein in roots prior to and during establishment of rhizobial symbiosis. Experiments show that LYK3-GFP dynamics and localization are affected by symbiotic bacteria in a Nod Factor signal-dependent manner and that postinoculation LYK3-GFP codistributes with a tagged plant flotillin.

The plastid ribosomal release factor-like protein PrfB3 arose from a gene duplication and has subsequently lost the two most important tripeptide motifs required for stop codon recognition and catalysis. This work shows that PrfB3 is essential in vascular plants and has been recruited for binding and environment-dependent stabilization of petB RNA to regulate cytochrome b₆f complex levels.

Whereas microtubules and cellulose synthase trajectories are transversely oriented on the outer epidermal surface of Arabidopsis hypocotyl cells only for part of the growth cycle, microtubules and microfibrils at the inner surface remain transverse throughout growth. The inner face of the epidermis is thus established as a regulator of growth anisotropy in the hypocotyl.

This work describes a Chlamydomonas mutant (pgrl1) isolated from a screen designed to identify new photosynthetic regulatory mechanisms. It provides evidence that in the wild type, photosynthetic electron supply to hydrogenase is severely limited by the proton gradient generated by cyclic electron flow, opening new perspective towards optimizing hydrogen production by microalgae.

In plants grown under field conditions, seed dormancy varies considerably with the time of year the seed is set, and this variation is important for the coordination of plant life history and seed quality. This work elucidates the mechanisms through which environmental temperature during seed set affects the germination behavior of seeds when released from the mother plant.

This work describes a Chlamydomonas mutant (pgrl1) isolated from a screen designed to identify new photosynthetic regulatory mechanisms. It provides evidence that in the wild type, photosynthetic electron supply to hydrogenase is severely limited by the proton gradient generated by cyclic electron flow, opening new perspective towards optimizing hydrogen production by microalgae.

The authors identified a bacterial monogalactosyldiacylglycerol synthase enzyme from Chlorobaculum tepidum. Using complementation analysis of a galactolipid synthase mutant of Arabidopsis, they revealed crucial roles of galactolipids for plant and bacterial photosynthesis. In addition, they investigated and discuss evolutionary paths of galactolipid biosynthesis in phototrophs.

The slow vacuolar channel is the dominant cation channel of the vacuolar membrane and is regulated by cytosolic as well as vacuolar calcium. Here, the vacuolar calcium binding site is characterized at the molecular level, adding to our understanding of calcium signaling in the extracytosolic space.

In plants grown under field conditions, seed dormancy varies considerably with the time of year the seed is set, and this variation is important for the coordination of plant life history and seed quality. This work elucidates the mechanisms through which environmental temperature during seed set affects the germination behavior of seeds when released from the mother plant.

This work identified two different Arabidopsis mutants that have reduced susceptibility to an infectious biotrophic pathogen due to overaccumulation of the amino acid Thr. This is detrimental for the host plant and the infecting pathogen but does not affect disease caused by some other pathogen species. Therefore, the host metabolic state can influence disease in quite a specific manner.

Whereas microtubules and cellulose synthase trajectories are transversely oriented on the outer epidermal surface of Arabidopsis hypocotyl cells only for part of the growth cycle, microtubules and microfibrils at the inner surface remain transverse throughout growth. The inner face of the epidermis is thus established as a regulator of growth anisotropy in the hypocotyl.

This work shows that the rice AGAMOUS-LIKE6 MADS box gene MADS6 acts as a master regulator in specifying floral organ identities and meristem determinacy through interaction with B-, C-, D-, and E-class floral homeotic genes.

This work identified two different Arabidopsis mutants that have reduced susceptibility to an infectious biotrophic pathogen due to overaccumulation of the amino acid Thr. This is detrimental for the host plant and the infecting pathogen but does not affect disease caused by some other pathogen species. Therefore, the host metabolic state can influence disease in quite a specific manner.

Two augmin complex proteins, which play a critical role in microtubule organization in the spindle and phragmoplast during cell division of plant cells, are identified in this study.

Ectopic expression of a MYB transcription factor, ODO1, in tomato fruit altered Phe and phenylpropanoid metabolism, as shown by metabolic profiling and flux analysis. This disruption permitted identification of a set of coregulated genes, including prephenate aminotransferase, which converts prephenate to arogenate. The results establish a fruit arogenate pathway for Phe synthesis.

Two augmin complex proteins, which play a critical role in microtubule organization in the spindle and phragmoplast during cell division of plant cells, are identified in this study.

Analysis of a series of mutants lacking each of the three isoforms of the Lhcb4 light-harvesting complex in Arabidopsis showed that this complex plays an important role in the macro-organization and photoprotection of photosystem II.

The plastid ribosomal release factor-like protein PrfB3 arose from a gene duplication and has subsequently lost the two most important tripeptide motifs required for stop codon recognition and catalysis. This work shows that PrfB3 is essential in vascular plants and has been recruited for binding and environment-dependent stabilization of petB RNA to regulate cytochrome b₆f complex levels.

This work analyzed genome-wide binding sites of a transposase-derived transcription factor, FHY3, using a chromatin immunoprecipitation–based sequencing approach and identified a role for FHY3 in controlling chloroplast development by directly activating the expression of ARC5, a key gene involved in chloroplast division.

This work analyzed genome-wide binding sites of a transposase-derived transcription factor, FHY3, using a chromatin immunoprecipitation–based sequencing approach and identified a role for FHY3 in controlling chloroplast development by directly activating the expression of ARC5, a key gene involved in chloroplast division.

This work shows that the rice AGAMOUS-LIKE6 MADS box gene MADS6 acts as a master regulator in specifying floral organ identities and meristem determinacy through interaction with B-, C-, D-, and E-class floral homeotic genes.

This work analyzed genome-wide binding sites of a transposase-derived transcription factor, FHY3, using a chromatin immunoprecipitation–based sequencing approach and identified a role for FHY3 in controlling chloroplast development by directly activating the expression of ARC5, a key gene involved in chloroplast division.

Two augmin complex proteins, which play a critical role in microtubule organization in the spindle and phragmoplast during cell division of plant cells, are identified in this study.

In plants grown under field conditions, seed dormancy varies considerably with the time of year the seed is set, and this variation is important for the coordination of plant life history and seed quality. This work elucidates the mechanisms through which environmental temperature during seed set affects the germination behavior of seeds when released from the mother plant.

The authors identified a bacterial monogalactosyldiacylglycerol synthase enzyme from Chlorobaculum tepidum. Using complementation analysis of a galactolipid synthase mutant of Arabidopsis, they revealed crucial roles of galactolipids for plant and bacterial photosynthesis. In addition, they investigated and discuss evolutionary paths of galactolipid biosynthesis in phototrophs.

The plastid ribosomal release factor-like protein PrfB3 arose from a gene duplication and has subsequently lost the two most important tripeptide motifs required for stop codon recognition and catalysis. This work shows that PrfB3 is essential in vascular plants and has been recruited for binding and environment-dependent stabilization of petB RNA to regulate cytochrome b₆f complex levels.

The slow vacuolar channel is the dominant cation channel of the vacuolar membrane and is regulated by cytosolic as well as vacuolar calcium. Here, the vacuolar calcium binding site is characterized at the molecular level, adding to our understanding of calcium signaling in the extracytosolic space.

The authors identified a bacterial monogalactosyldiacylglycerol synthase enzyme from Chlorobaculum tepidum. Using complementation analysis of a galactolipid synthase mutant of Arabidopsis, they revealed crucial roles of galactolipids for plant and bacterial photosynthesis. In addition, they investigated and discuss evolutionary paths of galactolipid biosynthesis in phototrophs.

The authors identified a bacterial monogalactosyldiacylglycerol synthase enzyme from Chlorobaculum tepidum. Using complementation analysis of a galactolipid synthase mutant of Arabidopsis, they revealed crucial roles of galactolipids for plant and bacterial photosynthesis. In addition, they investigated and discuss evolutionary paths of galactolipid biosynthesis in phototrophs.

This work identified two different Arabidopsis mutants that have reduced susceptibility to an infectious biotrophic pathogen due to overaccumulation of the amino acid Thr. This is detrimental for the host plant and the infecting pathogen but does not affect disease caused by some other pathogen species. Therefore, the host metabolic state can influence disease in quite a specific manner.

This work describes a Chlamydomonas mutant (pgrl1) isolated from a screen designed to identify new photosynthetic regulatory mechanisms. It provides evidence that in the wild type, photosynthetic electron supply to hydrogenase is severely limited by the proton gradient generated by cyclic electron flow, opening new perspective towards optimizing hydrogen production by microalgae.