bims-plasge 2024-03-31 papers

Mol Breed. 2024 Apr;44(4): 29

OsPGL3A encodes a DYW-type pentatricopeptide repeat protein involved in chloroplast RNA processing and regulated chloroplast development.

Min Xu, Xinying Zhang, Jinzhe Cao, Jiali Liu, Yiyuan He, Qingjie Guan, Xiaojie Tian, Jiaqi Tang, Xiufeng Li, Deyong Ren, Qingyun Bu, Zhenyu Wang.

The chloroplast serves as the primary site of photosynthesis, and its development plays a crucial role in regulating plant growth and morphogenesis. The Pentatricopeptide Repeat Sequence (PPR) proteins constitute a vast protein family that function in the post-transcriptional modification of RNA within plant organelles. In this study, we characterized mutant of rice with pale green leaves (pgl3a). The chlorophyll content of pgl3a at the seedling stage was significantly reduced compared to the wild type (WT). Transmission electron microscopy (TEM) and quantitative PCR analysis revealed that pgl3a exhibited aberrant chloroplast development compared to the wild type (WT), accompanied by significant alterations in gene expression levels associated with chloroplast development and photosynthesis. The Mutmap analysis revealed that a single base deletionin the coding region of Os03g0136700 in pgl3a. By employing CRISPR/Cas9 mediated gene editing, two homozygous cr-pgl3a mutants were generated and exhibited a similar phenotype to pgl3a, thereby confirming that Os03g0136700 was responsible for pgl3a. Consequently, it was designated as OsPGL3A. OsPGL3A belongs to the DYW-type PPR protein family and is localized in chloroplasts. Furthermore, we demonstrated that the RNA editing efficiency of rps8-182 and rpoC2-4106, and the splicing efficiency of ycf3-1 were significantly decreased in pgl3a mutants compared to WT. Collectively, these results indicate that OsPGL3A plays a crucial role in chloroplast development by regulating the editing and splicing of chloroplast genes in rice.Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01468-7.

Keywords: Chloroplast development; Oryza sativa; Pentatricopeptide repeat (PPR) protein; RNA editing; RNA splicing

DOI: https://doi.org/10.1007/s11032-024-01468-7

Front Plant Sci. 2024 ;15 1359117

Identification of QTLs associated with seed protein concentration in two diverse recombinant inbred line populations of pea.

Krishna Kishore Gali, Ambuj Jha, Bunyamain Tar'an, Judith Burstin, Gregoire Aubert, Dengjin Bing, Gene Arganosa, Thomas D Warkentin.

Improving the seed protein concentration (SPC) of pea (Pisum sativum L.) has turned into an important breeding objective because of the consumer demand for plant-based protein and demand from protein fractionation industries. To support the marker-assisted selection (MAS) of SPC towards accelerated breeding of improved cultivars, we have explored two diverse recombinant inbred line (RIL) populations to identify the quantitative trait loci (QTLs) associated with SPC. The two RIL populations, MP 1918 × P0540-91 (PR-30) and Ballet × Cameor (PR-31), were derived from crosses between moderate SPC × high SPC accessions. A total of 166 and 159 RILs of PR-30 and PR-31, respectively, were genotyped using an Axiom® 90K SNP array and 13.2K SNP arrays, respectively. The RILs were phenotyped in replicated trials in two and three locations of Saskatchewan, Canada in 2020 and 2021, respectively, for agronomic assessment and SPC. Using composite interval mapping, we identified three QTLs associated with SPC in PR-30 and five QTLs in PR-31, with the LOD value ranging from 3.0 to 11.0. A majority of these QTLs were unique to these populations compared to the previously known QTLs for SPC. The QTL SPC-Ps-5.1 overlapped with the earlier reported SPC associated QTL PC-QTL-3. Three QTLs, SPC-Ps-4.2, SPC-Ps-5.1, and SPC-Ps-7.2 with LOD scores of 7.2, 7.9, and 11.3, and which explained 14.5%, 11.6%, and 11.3% of the phenotypic variance, respectively, can be used for marker-assisted breeding to increase SPC in peas. Eight QTLs associated with the grain yield were identified with LOD scores ranging from 3.1 to 8.2. Two sets of QTLs, SPC-Ps-2.1 and GY-Ps-2.1, and SPC-Ps-5.1 and GY-Ps-5.3, shared the QTL/peak regions. Each set of QTLs contributed to either SPC or grain yield depending on which parent the QTL region is derived from, thus confirming that breeding for SPC should take into consideration the effects on grain yield.

Keywords: Pisum sativum; QTL; SNP genotyping; marker-assisted selection; vegetable protein

DOI: https://doi.org/10.3389/fpls.2024.1359117

Int J Mol Sci. 2024 Mar 21. pii: 3542. [Epub ahead of print]25(6):

PPR596 Is Required for nad2 Intron Splicing and Complex I Biogenesis in Arabidopsis.

Aqib Sayyed, Baoyin Chen, Yong Wang, Shi-Kai Cao, Bao-Cai Tan.

Mitochondria are essential organelles that generate energy via oxidative phosphorylation. Plant mitochondrial genome encodes some of the respiratory complex subunits, and these transcripts require accurate processing, including C-to-U RNA editing and intron splicing. Pentatricopeptide repeats (PPR) proteins are involved in various organellar RNA processing events. PPR596, a P-type PPR protein, was previously identified to function in the C-to-U editing of mitochondrial rps3 transcripts in Arabidopsis. Here, we demonstrate that PPR596 functions in the cis-splicing of nad2 intron 3 in mitochondria. Loss of the PPR596 function affects the editing at rps3eU1344SS, impairs nad2 intron 3 splicing and reduces the mitochondrial complex I's assembly and activity, while inducing alternative oxidase (AOX) gene expression. This defect in nad2 intron splicing provides a plausible explanation for the slow growth of the ppr595 mutants. Although a few P-type PPR proteins are involved in RNA C-to-U editing, our results suggest that the primary function of PPR596 is intron splicing.

Keywords: Arabidopsis; C-to-U RNA editing; PPR596; complex I assembly; mitochondrial respiratory chain; nad2 intron splicing

DOI: https://doi.org/10.3390/ijms25063542