bims-plasge 2024-07-28 papers

Int J Mol Sci. 2024 Jul 19. pii: 7920. [Epub ahead of print]25(14):

Genome-Wide Association Studies on Resistance to Pea Weevil: Identification of Novel Sources of Resistance and Associated Markers.

Salvador Osuna-Caballero, María J Cobos, Carmen M Ruiz, Osman Z Wohor, Nicolas Rispail, Diego Rubiales.

Little resistance to the pea weevil insect pest (Bruchus pisorum) is available in pea (Pisum sativum) cultivars, highlighting the need to search for sources of resistance in Pisum germplasm and to decipher the genetic basis of resistance. To address this need, we screened the response to pea weevil in a Pisum germplasm collection (324 accession, previously genotyped) under field conditions over four environments. Significant variation for weevil seed infestation (SI) was identified, with resistance being frequent in P. fulvum, followed by P. sativum ssp. elatius, P. abyssinicum, and P. sativum ssp. humile. SI tended to be higher in accessions with lighter seed color. SI was also affected by environmental factors, being favored by high humidity during flowering and hampered by warm winter temperatures and high evapotranspiration during and after flowering. Merging the phenotypic and genotypic data allowed genome-wide association studies (GWAS) yielding 73 markers significantly associated with SI. Through the GWAS models, 23 candidate genes were found associated with weevil resistance, highlighting the interest of five genes located on chromosome 6. These included gene 127136761 encoding squalene epoxidase; gene 127091639 encoding a transcription factor MYB SRM1; gene 127097033 encoding a 60S ribosomal protein L14; gene 127092211, encoding a BolA-like family protein, which, interestingly, was located within QTL BpLD.I, earlier described as conferring resistance to weevil in pea; and gene 127096593 encoding a methyltransferase. These associated genes offer valuable potential for developing pea varieties resistant to Bruchus spp. and efficient utilization of genomic resources through marker-assisted selection (MAS).

Keywords: Bruchus; GWAS; Pisum; resistance breeding

DOI: https://doi.org/10.3390/ijms25147920

Curr Issues Mol Biol. 2024 Jun 27. 46(7): 6508-6521

Mapping and Candidate Gene Analysis of the Low-Temperature-Sensitive Albino Gene OsLTSA8 in Rice Seedlings.

Yu Wei, Xiaoqiong Li, Dongxiu Li, Xuejun Su, Yunchuan Huang, Qiuwen Li, Manling Liang, Xinghai Yang.

Chloroplasts are organelles responsible for photosynthesis in plants, providing energy for growth and development. However, the genetic regulatory mechanisms underlying early chloroplast development in rice remain incompletely understood. In this study, we identified a rice seedling thermosensitive chlorophyll-deficient mutant, osltsa8, and the genetic analysis of two F2 populations suggested that this trait may be controlled by more than one pair of alleles. Through reciprocal F2 populations and QTL-seq technology, OsLTSA8 was mapped to the interval of 24,280,402-25,920,942 bp on rice chromosome 8, representing a novel albino gene in rice. Within the candidate gene region of OsLTSA8, there were 258 predicted genes, among which LOC_Os08g39050, LOC_Os08g39130, and LOC_Os08g40870 encode pentatricopeptide repeat (PPR) proteins. RNA-seq identified 18 DEGs (differentially expressed genes) within the candidate interval, with LOC_Os08g39420 showing homology to the pigment biosynthesis-related genes Zm00001d017656 and Sb01g000470; LOC_Os08g39430 and LOC_Os08g39850 were implicated in chlorophyll precursor synthesis. RT-qPCR was employed to assess the expression levels of LOC_Os08g39050, LOC_Os08g39130, LOC_Os08g40870, LOC_Os08g39420, LOC_Os08g39430, and LOC_Os08g39850 in the wild-type and mutant plants. Among them, the differences in the expression levels of LOC_Os08g39050 and LOC_Os08g39430 were the most significant. This study will contribute to further elucidating the molecular mechanisms of rice chloroplast development.

Keywords: QTL-seq; RNA-seq; albino; candidate genes; low temperature; rice

DOI: https://doi.org/10.3390/cimb46070388

Int J Mol Sci. 2024 Jul 17. pii: 7829. [Epub ahead of print]25(14):

Mitochondrial ATP Synthase beta-Subunit Affects Plastid Retrograde Signaling in Arabidopsis.

Hao Liu, Zhixin Liu, Aizhi Qin, Yaping Zhou, Susu Sun, Yumeng Liu, Mengke Hu, Jincheng Yang, Xuwu Sun.

Plastid retrograde signaling plays a key role in coordinating the expression of plastid genes and photosynthesis-associated nuclear genes (PhANGs). Although plastid retrograde signaling can be substantially compromised by mitochondrial dysfunction, it is not yet clear whether specific mitochondrial factors are required to regulate plastid retrograde signaling. Here, we show that mitochondrial ATP synthase beta-subunit mutants with decreased ATP synthase activity are impaired in plastid retrograde signaling in Arabidopsis thaliana. Transcriptome analysis revealed that the expression levels of PhANGs were significantly higher in the mutants affected in the AT5G08670 gene encoding the mitochondrial ATP synthase beta-subunit, compared to wild-type (WT) seedlings when treated with lincomycin (LIN) or norflurazon (NF). Further studies indicated that the expression of nuclear genes involved in chloroplast and mitochondrial retrograde signaling was affected in the AT5G08670 mutant seedlings treated with LIN. These changes might be linked to the modulation of some transcription factors (TFs), such as LHY (Late Elongated Hypocotyl), PIF (Phytochrome-Interacting Factors), MYB, WRKY, and AP2/ERF (Ethylene Responsive Factors). These findings suggest that the activity of mitochondrial ATP synthase significantly influences plastid retrograde signaling.

Keywords: AT5G08670; ATP synthase activity; ATP synthase beta-subunit; mitochondrial protein; plastid retrograde signaling

DOI: https://doi.org/10.3390/ijms25147829