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Multiple interval QTL mapping and searching for PSTOL1 homologs associated with root morphology, biomass accumulation and phosphorus content in maize seedlings under low-P.

Azevedo GC, Cheavegatti-Gianotto A, Negri BF, Hufnagel B, E Silva Lda C, Magalhaes JV, Garcia AA, Lana UG, de Sousa SM, Guimaraes CT - BMC Plant Biol. (2015)

Bottom Line: Multiple interval mapping models for single (MIM) and multiple traits (MT-MIM) were combined and revealed 13 genomic regions significantly associated with the target traits in a complementary way.QTL mapping strategies adopted in this study revealed complementary results for single and multiple traits with high accuracy.Some QTLs, mainly the ones that were also associated with yield performance in other studies, can be good targets for marker-assisted selection to improve P-use efficiency in maize.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Belo Horizonte, MG, 31270-901, Brazil. gabrielcorradiazevedo@yahoo.com.br.

ABSTRACT

Background: Modifications in root morphology are important strategies to maximize soil exploitation under phosphorus starvation in plants. Here, we used two multiple interval models to map QTLs related to root traits, biomass accumulation and P content in a maize RIL population cultivated in nutrient solution. In addition, we searched for putative maize homologs to PSTOL1, a gene responsible to enhance early root growth, P uptake and grain yield in rice and sorghum.

Results: Based on path analysis, root surface area was the root morphology component that most strongly contributed to total dry weight and to P content in maize seedling under low-P availability. Multiple interval mapping models for single (MIM) and multiple traits (MT-MIM) were combined and revealed 13 genomic regions significantly associated with the target traits in a complementary way. The phenotypic variances explained by all QTLs and their epistatic interactions using MT-MIM (23.4 to 35.5 %) were higher than in previous studies, and presented superior statistical power. Some of these QTLs were coincident with QTLs for root morphology traits and grain yield previously mapped, whereas others harbored ZmPSTOL candidate genes, which shared more than 55 % of amino acid sequence identity and a conserved serine/threonine kinase domain with OsPSTOL1. Additionally, four ZmPSTOL candidate genes co-localized with QTLs for root morphology, biomass accumulation and/or P content were preferentially expressed in roots of the parental lines that contributed the alleles enhancing the respective phenotypes.

Conclusions: QTL mapping strategies adopted in this study revealed complementary results for single and multiple traits with high accuracy. Some QTLs, mainly the ones that were also associated with yield performance in other studies, can be good targets for marker-assisted selection to improve P-use efficiency in maize. Based on the co-localization with QTLs, the protein domain conservation and the coincidence of gene expression, we selected novel maize genes as putative homologs to PSTOL1 that will require further validation studies.

No MeSH data available.


Phylogenetic tree of predicted serine/theronine receptor-like kinases from maize, rice and Arabidopsis thaliana. The rice PSTOL1, the six maize proteins sharing more than 55 % sequence identity to OsPSTOL1, PR5K and SNC4 from Arabidopsis thaliana were grouped separately from other rice kinases, and are highlighted. Numbers on branches are bootstrap values for the percentage of coincidence (%) inferred from 1,000 replicates. Only percentage values higher than 50 % are shown
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Fig3: Phylogenetic tree of predicted serine/theronine receptor-like kinases from maize, rice and Arabidopsis thaliana. The rice PSTOL1, the six maize proteins sharing more than 55 % sequence identity to OsPSTOL1, PR5K and SNC4 from Arabidopsis thaliana were grouped separately from other rice kinases, and are highlighted. Numbers on branches are bootstrap values for the percentage of coincidence (%) inferred from 1,000 replicates. Only percentage values higher than 50 % are shown

Mentions: A phylogenetic analysis revealed that the six predicted ZmPSTOL proteins clustered together with PSTOL1 from rice, SNC4 and PR5 from Arabidopsis (circled in Fig. 3), which were classified as LRK10L-2 subfamily of serine/threonine receptor-like kinases by Gamuyao et al. [40]. In a detailed alignment of structural predictions, all maize PSTOL-like proteins shared conserved ATP-binding and serine/threonine protein kinase domains with OsPSTOL1 (Additional file 3: Figure S2). A distinct glycosyl hydrolase domain was predicted for ZmPSTOL4.05. The maize proteins ZmPSTOL4.05, ZmPSTOL8.02, ZmPSTOL8.05_1 and ZmPSTOL8.05_2 were classified as receptor-like kinases (RLKs), which are characterized by the presence of a transmembrane domain for signal perception and an intracellular kinase domain [48, 49]. In contrast, the proteins ZmPSTOL3.04 and ZmPSTOL3.06 contained the intracellular kinase domain but lacked the transmembrane domain similarly to OsPSTOL1 [40], and thus were classified as receptor-like cytoplasmic kinases (RLCKs) [49].Fig. 3


Multiple interval QTL mapping and searching for PSTOL1 homologs associated with root morphology, biomass accumulation and phosphorus content in maize seedlings under low-P.

Azevedo GC, Cheavegatti-Gianotto A, Negri BF, Hufnagel B, E Silva Lda C, Magalhaes JV, Garcia AA, Lana UG, de Sousa SM, Guimaraes CT - BMC Plant Biol. (2015)

Phylogenetic tree of predicted serine/theronine receptor-like kinases from maize, rice and Arabidopsis thaliana. The rice PSTOL1, the six maize proteins sharing more than 55 % sequence identity to OsPSTOL1, PR5K and SNC4 from Arabidopsis thaliana were grouped separately from other rice kinases, and are highlighted. Numbers on branches are bootstrap values for the percentage of coincidence (%) inferred from 1,000 replicates. Only percentage values higher than 50 % are shown
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4492167&req=5

Fig3: Phylogenetic tree of predicted serine/theronine receptor-like kinases from maize, rice and Arabidopsis thaliana. The rice PSTOL1, the six maize proteins sharing more than 55 % sequence identity to OsPSTOL1, PR5K and SNC4 from Arabidopsis thaliana were grouped separately from other rice kinases, and are highlighted. Numbers on branches are bootstrap values for the percentage of coincidence (%) inferred from 1,000 replicates. Only percentage values higher than 50 % are shown
Mentions: A phylogenetic analysis revealed that the six predicted ZmPSTOL proteins clustered together with PSTOL1 from rice, SNC4 and PR5 from Arabidopsis (circled in Fig. 3), which were classified as LRK10L-2 subfamily of serine/threonine receptor-like kinases by Gamuyao et al. [40]. In a detailed alignment of structural predictions, all maize PSTOL-like proteins shared conserved ATP-binding and serine/threonine protein kinase domains with OsPSTOL1 (Additional file 3: Figure S2). A distinct glycosyl hydrolase domain was predicted for ZmPSTOL4.05. The maize proteins ZmPSTOL4.05, ZmPSTOL8.02, ZmPSTOL8.05_1 and ZmPSTOL8.05_2 were classified as receptor-like kinases (RLKs), which are characterized by the presence of a transmembrane domain for signal perception and an intracellular kinase domain [48, 49]. In contrast, the proteins ZmPSTOL3.04 and ZmPSTOL3.06 contained the intracellular kinase domain but lacked the transmembrane domain similarly to OsPSTOL1 [40], and thus were classified as receptor-like cytoplasmic kinases (RLCKs) [49].Fig. 3

Bottom Line: Multiple interval mapping models for single (MIM) and multiple traits (MT-MIM) were combined and revealed 13 genomic regions significantly associated with the target traits in a complementary way.QTL mapping strategies adopted in this study revealed complementary results for single and multiple traits with high accuracy.Some QTLs, mainly the ones that were also associated with yield performance in other studies, can be good targets for marker-assisted selection to improve P-use efficiency in maize.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Belo Horizonte, MG, 31270-901, Brazil. gabrielcorradiazevedo@yahoo.com.br.

ABSTRACT

Background: Modifications in root morphology are important strategies to maximize soil exploitation under phosphorus starvation in plants. Here, we used two multiple interval models to map QTLs related to root traits, biomass accumulation and P content in a maize RIL population cultivated in nutrient solution. In addition, we searched for putative maize homologs to PSTOL1, a gene responsible to enhance early root growth, P uptake and grain yield in rice and sorghum.

Results: Based on path analysis, root surface area was the root morphology component that most strongly contributed to total dry weight and to P content in maize seedling under low-P availability. Multiple interval mapping models for single (MIM) and multiple traits (MT-MIM) were combined and revealed 13 genomic regions significantly associated with the target traits in a complementary way. The phenotypic variances explained by all QTLs and their epistatic interactions using MT-MIM (23.4 to 35.5 %) were higher than in previous studies, and presented superior statistical power. Some of these QTLs were coincident with QTLs for root morphology traits and grain yield previously mapped, whereas others harbored ZmPSTOL candidate genes, which shared more than 55 % of amino acid sequence identity and a conserved serine/threonine kinase domain with OsPSTOL1. Additionally, four ZmPSTOL candidate genes co-localized with QTLs for root morphology, biomass accumulation and/or P content were preferentially expressed in roots of the parental lines that contributed the alleles enhancing the respective phenotypes.

Conclusions: QTL mapping strategies adopted in this study revealed complementary results for single and multiple traits with high accuracy. Some QTLs, mainly the ones that were also associated with yield performance in other studies, can be good targets for marker-assisted selection to improve P-use efficiency in maize. Based on the co-localization with QTLs, the protein domain conservation and the coincidence of gene expression, we selected novel maize genes as putative homologs to PSTOL1 that will require further validation studies.

No MeSH data available.