Limits...
The rice ALS3 encoding a novel pentatricopeptide repeat protein is required for chloroplast development and seedling growth.

Lin D, Gong X, Jiang Q, Zheng K, Zhou H, Xu J, Teng S, Dong Y - Rice (N Y) (2015)

Bottom Line: Moreover, expression analysis revealed that the asl3 mutation severely affected the transcriptional levels of important genes associated with plastid translation machinery and photosynthesis, which may impair photosynthesis and finally led to the seedling death in asl3 mutant.These results evidenced the important role of ASL3 in the early development of rice, especially chloroplast development.Disruption of the ASL3 would lead to a defective chloroplast and seedling lethality, and affected expression levels of genes associated with chloroplast development and photosynthesis at early leaf stage of rice.

View Article: PubMed Central - PubMed

Affiliation: Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234 China.

ABSTRACT

Background: Pentatricopeptide repeat (PPR) proteins play essential roles in modulating the expression of organelle genes and have expanded greatly in higher plants. However, molecular mechanisms of most rice PPR genes remain unclear.

Results: In this study, a new rice PPR mutant, asl3 (albino seedling lethality3) exhibits an albino lethal phenotype at the seedling stage. This albino phenotype was associated with altered photosynthetic-pigment and chloroplast development. Map-based cloning showed that ASL3 encodes a novel rice PPR protein with 10 tandem PPR motifs, which localizes to the chloroplast. ASL3 showed tissue-specific expression, as it was highly expressed in the chlorenchyma, but expressed at much lower levels in roots and panicles. RNAi of ASL3 confirmed that ASL3 plays an essential role in the early development and chloroplast development in rice. Moreover, expression analysis revealed that the asl3 mutation severely affected the transcriptional levels of important genes associated with plastid translation machinery and photosynthesis, which may impair photosynthesis and finally led to the seedling death in asl3 mutant. These results evidenced the important role of ASL3 in the early development of rice, especially chloroplast development.

Conclusions: The ASL3 gene encoded a novel chloroplast-targeted PPR protein with 10 tandem PPR motifs in rice. Disruption of the ASL3 would lead to a defective chloroplast and seedling lethality, and affected expression levels of genes associated with chloroplast development and photosynthesis at early leaf stage of rice.

No MeSH data available.


Related in: MedlinePlus

Subcellular localization of the ASL3’ protein: (A) A tobacco mesophyll cell expressing ASL3–GFP; (B) A tobacco epidermal cell expressing GFP alone The scale bar represents 20 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4390607&req=5

Fig6: Subcellular localization of the ASL3’ protein: (A) A tobacco mesophyll cell expressing ASL3–GFP; (B) A tobacco epidermal cell expressing GFP alone The scale bar represents 20 μm.

Mentions: The ASL3 protein was predicted to localize to chloroplasts according to ChloroP (http://www.cbs.dtu.dk/services/ChloroP/) and TargetP (http://www.cbs.dtu.dk/services/TargetP/). To examine the actual subcellular localization of ASL3, the cDNA fragment encoding the N-terminal region (amino acids 1–249) of the ASL3 was amplified from WT plants and introduced into the N-terminal of the GFP gene in the expression vector pMON530-GFP. The pMON530:CaMV35S:ASL3-GFP plasmid was introduced into tobacco cells using Agrobacterium-mediated infection method. Meanwhile, empty GFP vector was used as a control. As a result, the green fluorescent signals of ASL3-GFP fusion protein perfectly overlapped with chloroplast autofluorescence in transformed tobacco mesophyll cells (Figure 6A). By contrast, the epidermis cells transformed with the empty GFP vector without a specific targeting sequence had green fluorescent signals in both plasma membrane, cytoplasm and the nucleus. Thus, these findings suggest that ASL3 is localized to the chloroplast (Figure 6B).Figure 6


The rice ALS3 encoding a novel pentatricopeptide repeat protein is required for chloroplast development and seedling growth.

Lin D, Gong X, Jiang Q, Zheng K, Zhou H, Xu J, Teng S, Dong Y - Rice (N Y) (2015)

Subcellular localization of the ASL3’ protein: (A) A tobacco mesophyll cell expressing ASL3–GFP; (B) A tobacco epidermal cell expressing GFP alone The scale bar represents 20 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390607&req=5

Fig6: Subcellular localization of the ASL3’ protein: (A) A tobacco mesophyll cell expressing ASL3–GFP; (B) A tobacco epidermal cell expressing GFP alone The scale bar represents 20 μm.
Mentions: The ASL3 protein was predicted to localize to chloroplasts according to ChloroP (http://www.cbs.dtu.dk/services/ChloroP/) and TargetP (http://www.cbs.dtu.dk/services/TargetP/). To examine the actual subcellular localization of ASL3, the cDNA fragment encoding the N-terminal region (amino acids 1–249) of the ASL3 was amplified from WT plants and introduced into the N-terminal of the GFP gene in the expression vector pMON530-GFP. The pMON530:CaMV35S:ASL3-GFP plasmid was introduced into tobacco cells using Agrobacterium-mediated infection method. Meanwhile, empty GFP vector was used as a control. As a result, the green fluorescent signals of ASL3-GFP fusion protein perfectly overlapped with chloroplast autofluorescence in transformed tobacco mesophyll cells (Figure 6A). By contrast, the epidermis cells transformed with the empty GFP vector without a specific targeting sequence had green fluorescent signals in both plasma membrane, cytoplasm and the nucleus. Thus, these findings suggest that ASL3 is localized to the chloroplast (Figure 6B).Figure 6

Bottom Line: Moreover, expression analysis revealed that the asl3 mutation severely affected the transcriptional levels of important genes associated with plastid translation machinery and photosynthesis, which may impair photosynthesis and finally led to the seedling death in asl3 mutant.These results evidenced the important role of ASL3 in the early development of rice, especially chloroplast development.Disruption of the ASL3 would lead to a defective chloroplast and seedling lethality, and affected expression levels of genes associated with chloroplast development and photosynthesis at early leaf stage of rice.

View Article: PubMed Central - PubMed

Affiliation: Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234 China.

ABSTRACT

Background: Pentatricopeptide repeat (PPR) proteins play essential roles in modulating the expression of organelle genes and have expanded greatly in higher plants. However, molecular mechanisms of most rice PPR genes remain unclear.

Results: In this study, a new rice PPR mutant, asl3 (albino seedling lethality3) exhibits an albino lethal phenotype at the seedling stage. This albino phenotype was associated with altered photosynthetic-pigment and chloroplast development. Map-based cloning showed that ASL3 encodes a novel rice PPR protein with 10 tandem PPR motifs, which localizes to the chloroplast. ASL3 showed tissue-specific expression, as it was highly expressed in the chlorenchyma, but expressed at much lower levels in roots and panicles. RNAi of ASL3 confirmed that ASL3 plays an essential role in the early development and chloroplast development in rice. Moreover, expression analysis revealed that the asl3 mutation severely affected the transcriptional levels of important genes associated with plastid translation machinery and photosynthesis, which may impair photosynthesis and finally led to the seedling death in asl3 mutant. These results evidenced the important role of ASL3 in the early development of rice, especially chloroplast development.

Conclusions: The ASL3 gene encoded a novel chloroplast-targeted PPR protein with 10 tandem PPR motifs in rice. Disruption of the ASL3 would lead to a defective chloroplast and seedling lethality, and affected expression levels of genes associated with chloroplast development and photosynthesis at early leaf stage of rice.

No MeSH data available.


Related in: MedlinePlus