Biology subjects

Tschiersch, H.

Publications and source records attributed to Tschiersch, H..

3 recordsLinked to original sources

bioRxiv2024

Natural variation in the Arabidopsis thaliana root and shoot response to boron deficiency reveals sensitive and responsive phenes and phylogenetic and geographic clustering of boron efficiency adaptations

O_LIBoron (B) is an essential plant micronutrient with a crucial role in cell wall stability. To improve plant tolerance to suboptimal B-availability, it is crucial to understand the mechanisms plants have evolved to tolerate B-limited conditions. C_LIO_LIWe assessed temporal physiological, ionomic and molecular responses to B-deficiency across a diversity panel of 185 Arabidopsis thaliana accessions. Plants were characterised in soil-substrate in an automated phenotyping system to track shoot performance, and on agar plates to track root traits. C_LIO_LIAccessions varied widely in their response to B-deficiency. Rosette area decreased by 50% under B-deficiency across all accessions on average but by less than 15% in B-efficient accessions alone. Most root traits suffered under B-deficiency but lateral root length increased in 20% of accessions. The B-uptake and B transporter expression response of B-efficient and B-inefficient accessions was similar, suggesting increased B-use rather than B-uptake efficiency in efficient accessions. Phylogenetic analysis demonstrated enrichment of B-efficient accessions within a clade containing accessions originating from areas characterised as B-deficient. K-means clustering revealed increased lateral root length was associated with efficient shoot growth under B-deficiency. C_LIO_LIThe results demonstrate different response strategies to B-deficiency, indicating target traits to improve the performance of plants grown under B-limiting conditions. C_LI

plant biology↗

bioRxiv2021

The Arabidopsis AAC Proteins CIL and CIA2 Are Sub-functionalized Paralogs involved in Chloroplast Development

The Arabidopsis gene Chloroplast Import Apparatus 2 (CIA2) encodes a transcription factor that positively affects the activity of nuclear genes for chloroplast ribosomal proteins and chloroplast protein import machineries. CIA2-like (CIL) is the paralogous gene of CIA2. We generated a cil mutant by site-directed mutagenesis and compared it with cia2 and cia2cil double mutant. Phenotype of the cil mutant did not differ from the wild type under our growth conditions, except faster growth and earlier time to flowering. Compared to cia2, the cia2cil mutant showed more impaired chloroplast functions and reduced amounts of plastid ribosomal RNAs. In silico analyses predict for CIA2 and CIL a C-terminal CCT domain and an N-terminal chloroplast transit peptide (cTP). Chloroplast (and potentially nuclear) localization was previously shown for HvCMF3 and HvCMF7, the homologs of CIA2 and CIL in barley. We observed nuclear localization of CIL after transient expression in Arabidopsis protoplasts. Surprisingly, transformation of cia2 with HvCMF3, HvCMF7 or with a truncated CIA2 lacking the predicted cTP could partially rescue the pale-green phenotype of cia2. These data are discussed with respect to potentially overlapping functions between CIA2, CIL and their barley homologs and to the function of the putative cTPs of CIA2 and CIL. HIGHLIGHTThe nucleus-localized CCT domain proteins CIA2 and CIL in Arabidopsis and the homologous chloroplast-localized HvCMF3 and HvCMF7 in barley retained partially overlapping functions in chloroplast development.

plant biology↗

bioRxiv2019

Mutation of the ALBOSTRIANS Ohnologous Gene HvCMF3 Impairs Chloroplast Development and Thylakoid Architecture in Barley due to Reduced Plastid Translation

Gene pairs resulting from whole genome duplication (WGD), so-called ohnologous genes, are retained only if at least one gene of the pair undergoes neo- or subfunctionalization. Sequence-based phylogenetic analyses of the ohnologous genes ALBOSTRIANS (HvAST/HvCMF7) and ALBOSTRIANS-LIKE (HvASL/HvCMF3) of barley (Hordeum vulgare) revealed that they belong to a newly identified subfamily of genes encoding CCT domain proteins with putative N-terminal chloroplast transit peptides. Recently, we showed that HvCMF7 is needed for chloroplast ribosome biogenesis. Here we demonstrate that mutations in HvCMF3 lead to seedlings delayed in development. They exhibit a xantha phenotype and successively develop pale green leaves. Compared to the wild type, plastids of the mutant seedlings show decreased PSII efficiency and lower amounts of ribosomal RNAs; they contain less thylakoids and grana with a higher number of more loosely stacked thylakoid membranes. Site-directed mutagenesis of HvCMF3 identified a previously unknown functional region, which is highly conserved within this subfamily of CCT domain containing proteins. HvCMF3:GFP fusion constructs localized to plastids. Hvcmf3Hvcmf7 double mutants indicated epistatic activity of HvCMF7 over HvCMF3. The chloroplast ribosome deficiency is discussed as the primary defect of the Hvcmf3 mutants. Our data suggests that HvCMF3 and HvCMF7 have similar but not identical functions.\n\nOne-sentence summaryPhylogenetic and mutant analyses of the barley protein HvCMF3 (ALBOSTRIANS-LIKE) identified, in higher plants, a subfamily of CCT domain proteins with essential function in chloroplast development.

genetics↗