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The New Phytologist Aug 2024The plant hormone ethylene is of vital importance in the regulation of plant development and stress responses. Recent studies revealed that...
The plant hormone ethylene is of vital importance in the regulation of plant development and stress responses. Recent studies revealed that 1-aminocyclopropane-1-carboxylic acid (ACC) plays a role beyond its function as an ethylene precursor. However, the absence of reliable methods to quantify ACC and its conjugates malonyl-ACC (MACC), glutamyl-ACC (GACC), and jasmonyl-ACC (JA-ACC) hinders related research. Combining synthetic and analytical chemistry, we present the first, validated methodology to rapidly extract and quantify ACC and its conjugates using ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). Its relevance was confirmed by application to Arabidopsis mutants with altered ACC metabolism and wild-type plants under stress. Pharmacological and genetic suppression of ACC synthesis resulted in decreased ACC and MACC content, whereas induction led to elevated levels. Salt, wounding, and submergence stress enhanced ACC and MACC production. GACC and JA-ACC were undetectable in vivo; however, GACC was identified in vitro, underscoring the broad applicability of the method. This method provides an efficient tool to study individual functions of ACC and its conjugates, paving the road toward exploration of novel avenues in ACC and ethylene metabolism, and revisiting ethylene literature in view of the recent discovery of an ethylene-independent role of ACC.
Topics: Arabidopsis; Ethylenes; Tandem Mass Spectrometry; Chromatography, High Pressure Liquid; Amino Acids, Cyclic; Biosynthetic Pathways; Stress, Physiological; Reproducibility of Results; Mutation; Liquid Chromatography-Mass Spectrometry
PubMed: 38849316
DOI: 10.1111/nph.19878 -
The New Phytologist Aug 2024
Topics: Oxylipins; Cyclopentanes; Gossypium; Stress, Physiological; Plant Proteins; Gene Expression Regulation, Plant; Signal Transduction; Adaptation, Physiological
PubMed: 38845449
DOI: 10.1111/nph.19884 -
The New Phytologist Aug 2024
Topics: Salt Tolerance; Quantitative Trait Loci; Genes, Plant; Arabidopsis; Gene Expression Regulation, Plant
PubMed: 38840572
DOI: 10.1111/nph.19887 -
The New Phytologist Jun 2024
PubMed: 38840568
DOI: 10.1111/nph.19892 -
The New Phytologist Jun 2024
PubMed: 38840567
DOI: 10.1111/nph.19890 -
The New Phytologist Aug 2024Throughout their lifecycle, plants are subjected to DNA damage from various sources, both environmental and endogenous. Investigating the mechanisms of the DNA damage...
Throughout their lifecycle, plants are subjected to DNA damage from various sources, both environmental and endogenous. Investigating the mechanisms of the DNA damage response (DDR) is essential to unravel how plants adapt to the changing environment, which can induce varying amounts of DNA damage. Using a combination of whole-mount single-molecule RNA fluorescence in situ hybridization (WM-smFISH) and plant cell cycle reporter lines, we investigated the transcriptional activation of a key homologous recombination (HR) gene, RAD51, in response to increasing amounts of DNA damage in Arabidopsis thaliana roots. The results uncover consistent variations in RAD51 transcriptional response and cell cycle arrest among distinct cell types and developmental zones. Furthermore, we demonstrate that DNA damage induced by genotoxic stress results in RAD51 transcription throughout the whole cell cycle, dissociating its traditional link with S/G2 phases. This work advances the current comprehension of DNA damage response in plants by demonstrating quantitative differences in DDR activation. In addition, it reveals new associations with the cell cycle and cell types, providing crucial insights for further studies of the broader response mechanisms in plants.
Topics: Arabidopsis; Plant Roots; DNA Damage; Cell Cycle; Gene Expression Regulation, Plant; Rad51 Recombinase; Arabidopsis Proteins; Transcription, Genetic
PubMed: 38840557
DOI: 10.1111/nph.19875 -
The New Phytologist Jun 2024Contemporary glaciers are inhabited by streptophyte algae that balance photosynthesis and growth with tolerance of low temperature, desiccation and UV radiation. These...
Contemporary glaciers are inhabited by streptophyte algae that balance photosynthesis and growth with tolerance of low temperature, desiccation and UV radiation. These same environmental challenges have been hypothesised as the driving force behind the evolution of land plants from streptophyte algal ancestors in the Cryogenian (720-635 million years ago). We sequenced, assembled and analysed the metagenome-assembled genome of the glacier alga Ancylonema nordenskiöldii to investigate its adaptations to life in ice, and whether this represents a vestige of Cryogenian exaptations. Phylogenetic analysis confirms the placement of glacier algae within the sister lineage to land plants, Zygnematophyceae. The metagenome-assembled genome is characterised by an expansion of genes involved in tolerance of high irradiance and UV light, while lineage-specific diversification is linked to the novel screening pigmentation of glacier algae. We found no support for the hypothesis of a common genomic basis for adaptations to ice and to land in streptophytes. Comparative genomics revealed that the reductive morphological evolution in the ancestor of Zygnematophyceae was accompanied by reductive genome evolution. This first genome-scale data for glacier algae suggests an Ancylonema-specific adaptation to the cryosphere, and sheds light on the genome evolution of land plants and Zygnematophyceae.
PubMed: 38840553
DOI: 10.1111/nph.19860 -
The New Phytologist Aug 2024Differences in demographic and environmental niches facilitate plant species coexistence in tropical forests. However, the adaptations that enable species to achieve...
Differences in demographic and environmental niches facilitate plant species coexistence in tropical forests. However, the adaptations that enable species to achieve higher demographic rates (e.g. growth or survival) or occupy unique environmental niches (e.g. waterlogged conditions) remain poorly understood. Anatomical traits may better predict plant environmental and demographic strategies because they are direct measurements of structures involved in these adaptations. We collected 18 leaf and twig traits from 29 tree species in a tropical freshwater swamp forest in Singapore. We estimated demographic parameters of the 29 species from growth and survival models, and degree of association toward swamp habitats. We examined pairwise trait-trait, trait-demography and trait-environment links while controlling for phylogeny. Leaf and twig anatomical traits were better predictors of all demographic parameters than other commonly measured leaf and wood traits. Plants with wider vessels had faster growth rates but lower survival rates. Leaf and spongy mesophyll thickness predicted swamp association. These findings demonstrate the utility of anatomical traits as indicators of plant hydraulic strategies and their links to growth-mortality trade-offs and waterlogging stress tolerance that underlie species coexistence mechanisms in tropical forest trees.
Topics: Plant Leaves; Tropical Climate; Trees; Adaptation, Physiological; Forests; Wetlands; Quantitative Trait, Heritable; Fresh Water; Ecosystem; Species Specificity
PubMed: 38840520
DOI: 10.1111/nph.19876 -
The New Phytologist Aug 2024The afila (af) mutation causes the replacement of leaflets by a branched mass of tendrils in the compound leaves of pea - Pisum sativum L. This mutation was first...
The afila (af) mutation causes the replacement of leaflets by a branched mass of tendrils in the compound leaves of pea - Pisum sativum L. This mutation was first described in 1953, and several reports of spontaneous af mutations and induced mutants with a similar phenotype exist. Despite widespread introgression into breeding material, the nature of af and the origin of the alleles used remain unknown. Here, we combine comparative genomics with reverse genetic approaches to elucidate the genetic determinants of af. We also investigate haplotype diversity using a set of AfAf and afaf cultivars and breeding lines and molecular markers linked to seven consecutive genes. Our results show that deletion of two tandemly arranged genes encoding Q-type Cys(2)His(2) zinc finger transcription factors, PsPALM1a and PsPALM1b, is responsible for the af phenotype in pea. Eight haplotypes were identified in the af-harbouring genomic region on chromosome 2. These haplotypes differ in the size of the deletion, covering more or less genes. Diversity at the af locus is valuable for crop improvement and sheds light on the history of pea breeding for improved standing ability. The results will be used to understand the function of PsPALM1a/b and to transfer the knowledge for innovation in related crops.
Topics: Pisum sativum; Haplotypes; Plant Breeding; Phenotype; Genes, Plant; Plant Proteins; Mutation; Plant Leaves; Breeding; Transcription Factors; Genetic Variation
PubMed: 38837425
DOI: 10.1111/nph.19800 -
The New Phytologist Jun 2024
PubMed: 38837421
DOI: 10.1111/nph.19881