bims-plasge 2021-09-26 papers

G3 (Bethesda). 2021 Sep 06. pii: jkab319. [Epub ahead of print]

The Gossypium anomalum genome as a resource for cotton improvement and evolutionary analysis of hybrid incompatibility.

Corrinne E Grover, Daojun Yuan, Mark A Arick, Emma R Miller, Guanjing Hu, Daniel G Peterson, Jonathan F Wendel, Joshua A Udall.

Cotton is an important crop that has been the beneficiary of multiple genome sequencing efforts, including diverse representatives of wild species for germplasm development. Gossypium anomalum is a wild African diploid species that harbors stress-resistance and fiber-related traits with potential application to modern breeding efforts. In addition, this species is a natural source of cytoplasmic male sterility and a resource for understanding hybrid lethality in the genus. Here, we report a high-quality de novo genome assembly for G. anomalum and characterize this genome relative to existing genome sequences in cotton. In addition, we use the synthetic allopolyploids 2(A2D1) and 2(A2D3) to discover regions in the G. anomalum genome potentially involved in hybrid lethality, a possibility enabled by introgression of regions homologous to the D3 (Gossypium davidsonii) lethality loci into the synthetic 2(A2D3) allopolyploid.

Keywords: Gossypium anomalum ; PacBio; genome sequence

DOI: https://doi.org/10.1093/g3journal/jkab319

J Plant Physiol. 2021 Sep 11. pii: S0176-1617(21)00160-7. [Epub ahead of print]266 153521

The knowns and unknowns of intracellular partitioning of carbon and nitrogen, with focus on the organic acid-mediated interplay between mitochondrion and chloroplast.

David B Medeiros, Fayezeh Aarabi, Félix Juan Martinez Rivas, Alisdair R Fernie.

The presence of specialized cellular compartments in higher plants express an extraordinary degree of intracellular organization, which provides efficient mechanisms to avoid misbalancing of the metabolism. This offers the flexibility by which plants can quickly acclimate to fluctuating environmental conditions. For that, a fine temporal and spatial regulation of metabolic pathways is required and involves several players e.g. organic acids. In this review we discuss different facets of the organic acid metabolism within plant cells with special focus to those related to the interactions between organic acids compartmentalization and the partitioning of carbon and nitrogen. The connections between organic acids and CO2 assimilation, tricarboxylic acid (TCA) cycle, amino acids metabolism, and redox status are highlighted. Moreover, the key enzymes and transporters as well as their function on the coordination of interorganellar metabolic exchanges are discussed.

Keywords: Malate; Photosynthesis; Redox status; Subcellular compartmentalization; TCA cycle

DOI: https://doi.org/10.1016/j.jplph.2021.153521

G3 (Bethesda). 2021 Sep 06. pii: jkab196. [Epub ahead of print]11(9):

Rice TSV2 encoding threonyl-tRNA synthetase is needed for early chloroplast development and seedling growth under cold stress.

Dongzhi Lin, Wenhao Zhou, Yulu Wang, Jia Sun, Xiaobiao Pan, Yanjun Dong.

Threonyl-tRNA synthetase (ThrRS), one of the aminoacyl-tRNA synthetases (AARSs), plays a crucial role in protein synthesis. However, the AARS functions on rice chloroplast development and growth were not fully appraised. In this study, a thermo-sensitive virescent mutant tsv2, which showed albino phenotype and lethal after the 4-leaf stage at 20°C but recovered to normal when the temperatures rose, was identified and characterized. Map-based cloning and complementation tests showed that TSV2 encoded a chloroplast-located ThrRS protein in rice. The Lys-to-Arg mutation in the anticodon-binding domain hampered chloroplast development under cold stress, while the loss of function of the ThrRS core domain in TSV2 fatally led to seedling death regardless of growing temperatures. In addition, TSV2 had a specific expression in early leaves. Its disruption obviously resulted in the downregulation of certain genes associated with chlorophyll biosynthesis, photosynthesis, and chloroplast development at cold conditions. Our observations revealed that rice nuclear-encoded TSV2 plays an important role in chloroplast development at the early leaf stage under cold stress.

Keywords: albino phenotype; chloroplast development; cold stress; rice; threonyl-tRNA synthetase

DOI: https://doi.org/10.1093/g3journal/jkab196