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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.


Related in: MedlinePlus

Expression profiles of the ZmPSTOL genes. The expression of the maize candidate genes are presented as relative gene expression (RQ) evaluated in roots and shoots of maize seedlings of the two parental lines L3 (P-efficient) and L22 (P-inefficient) grown under two levels of P (2.5 and 250 μM) after 13 days of treatment. Error bars indicate the standard errors of three technical replicates composed of three seedlings each
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Fig4: Expression profiles of the ZmPSTOL genes. The expression of the maize candidate genes are presented as relative gene expression (RQ) evaluated in roots and shoots of maize seedlings of the two parental lines L3 (P-efficient) and L22 (P-inefficient) grown under two levels of P (2.5 and 250 μM) after 13 days of treatment. Error bars indicate the standard errors of three technical replicates composed of three seedlings each

Mentions: The expression analyses revealed that ZmPSTOL4.05, ZmPSTOL8.02 and ZmPSTOL8.05_1 were highly and consistently expressed in the roots of the P-inefficient genotype (L22) under low (2.5 μM) and high (250 μM) P conditions, but were not responsive to P in either L22 or L3 (Fig. 4). ZmPSTOL3.06 was preferentially expressed in the roots of the P-efficient line (L3) with lower expression under high-P compared to the low-P concentration, and induced by high-P in roots of L22 (Fig. 4). The expression of ZmPSTOL3.04 and ZmPSTOL8.05_2 was induced in the root and repressed in the shoot of L22 under high-P concentration, but were not differentially expressed in L3 (Fig. 4). Additionally, the expression pattern of ZmPSTOL3.04 and ZmPSTOL8.05_2 in roots may reflect the total P content in the seedling, whereas the expression in shoots could be negatively associated with the total P content in L22 (Additional file 4: Table S2).Fig. 4


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)

Expression profiles of the ZmPSTOL genes. The expression of the maize candidate genes are presented as relative gene expression (RQ) evaluated in roots and shoots of maize seedlings of the two parental lines L3 (P-efficient) and L22 (P-inefficient) grown under two levels of P (2.5 and 250 μM) after 13 days of treatment. Error bars indicate the standard errors of three technical replicates composed of three seedlings each
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig4: Expression profiles of the ZmPSTOL genes. The expression of the maize candidate genes are presented as relative gene expression (RQ) evaluated in roots and shoots of maize seedlings of the two parental lines L3 (P-efficient) and L22 (P-inefficient) grown under two levels of P (2.5 and 250 μM) after 13 days of treatment. Error bars indicate the standard errors of three technical replicates composed of three seedlings each
Mentions: The expression analyses revealed that ZmPSTOL4.05, ZmPSTOL8.02 and ZmPSTOL8.05_1 were highly and consistently expressed in the roots of the P-inefficient genotype (L22) under low (2.5 μM) and high (250 μM) P conditions, but were not responsive to P in either L22 or L3 (Fig. 4). ZmPSTOL3.06 was preferentially expressed in the roots of the P-efficient line (L3) with lower expression under high-P compared to the low-P concentration, and induced by high-P in roots of L22 (Fig. 4). The expression of ZmPSTOL3.04 and ZmPSTOL8.05_2 was induced in the root and repressed in the shoot of L22 under high-P concentration, but were not differentially expressed in L3 (Fig. 4). Additionally, the expression pattern of ZmPSTOL3.04 and ZmPSTOL8.05_2 in roots may reflect the total P content in the seedling, whereas the expression in shoots could be negatively associated with the total P content in L22 (Additional file 4: Table S2).Fig. 4

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.


Related in: MedlinePlus