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A High Temperature-Dependent Mitochondrial Lipase EXTRA GLUME1 Promotes Floral Phenotypic Robustness against Temperature Fluctuation in Rice (Oryza sativa L.).

Zhang B, Wu S, Zhang Y, Xu T, Guo F, Tang H, Li X, Wang P, Qian W, Xue Y - PLoS Genet. (2016)

Bottom Line: In this study, we found that eg1 (extra glume1) mutants of rice (Oryza savita L.) showed floral phenotypic variations in different growth locations resulting in a breakdown of floral identity robustness.Furthermore, we found that numerous environmentally responsive genes including many floral identity genes are transcriptionally repressed in eg1 mutants and OsMADS1, OsMADS6 and OsG1 genetically act downstream of EG1 to maintain floral robustness.Collectively, our results demonstrate that EG1 promotes floral robustness against temperature fluctuation by safeguarding the expression of floral identify genes through a high temperature-dependent mitochondrial lipid pathway and uncovers a novel mechanistic insight into floral developmental control.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences and National Center for Plant Gene Research, Beijing, the People's Republic of China.

ABSTRACT
The sessile plants have evolved diverse intrinsic mechanisms to control their proper development under variable environments. In contrast to plastic vegetative development, reproductive traits like floral identity often show phenotypic robustness against environmental variations. However, it remains obscure about the molecular basis of this phenotypic robustness. In this study, we found that eg1 (extra glume1) mutants of rice (Oryza savita L.) showed floral phenotypic variations in different growth locations resulting in a breakdown of floral identity robustness. Physiological and biochemical analyses showed that EG1 encodes a predominantly mitochondria-localized functional lipase and functions in a high temperature-dependent manner. Furthermore, we found that numerous environmentally responsive genes including many floral identity genes are transcriptionally repressed in eg1 mutants and OsMADS1, OsMADS6 and OsG1 genetically act downstream of EG1 to maintain floral robustness. Collectively, our results demonstrate that EG1 promotes floral robustness against temperature fluctuation by safeguarding the expression of floral identify genes through a high temperature-dependent mitochondrial lipid pathway and uncovers a novel mechanistic insight into floral developmental control.

No MeSH data available.


Related in: MedlinePlus

Subspecific variations of eg1 floral plasticity.(a) Floral plasticity of eg1 alleles in two exchanged backgrounds. eg1-1 (ZF802>ZH11) and eg1-2 (ZH11>ZF802) show eg1-1 and eg1-2 backcrossed into ZH11 or ZF802 backgrounds, respectively. (b) Floral plasticity of eg1-4 in indica Dular background. Statistical analysis of two types of panicles according to rs (Type I and Type II) are shown. (c) Floral plasticity of eg1-5 and -6 in japonica Nipponbare background. Statistical analysis of the two independent lines are shown. LS Feb, Lingshui Feb. LS Apr, Lingshui Apr. Beijing, Beijing summer. Lingshui, Lingshui winter. Variable phenotypes of spikelets are defined as in S1 Table, and percentages of them in a panicle are shown in the y axis. le, lemma; pa, palea; st, stamen; eg, empty glume; if, inflorescence primordia; sp, smaller pa; lel, lemma-like organ; pl, palea-lemma mosaic organ. Bars = 2 mm. Values are means ± SE, number of analyzed panicles ≥ 5, and significant difference was determined by ANOVA, *P < 0.05, **P < 0.01.
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pgen.1006152.g002: Subspecific variations of eg1 floral plasticity.(a) Floral plasticity of eg1 alleles in two exchanged backgrounds. eg1-1 (ZF802>ZH11) and eg1-2 (ZH11>ZF802) show eg1-1 and eg1-2 backcrossed into ZH11 or ZF802 backgrounds, respectively. (b) Floral plasticity of eg1-4 in indica Dular background. Statistical analysis of two types of panicles according to rs (Type I and Type II) are shown. (c) Floral plasticity of eg1-5 and -6 in japonica Nipponbare background. Statistical analysis of the two independent lines are shown. LS Feb, Lingshui Feb. LS Apr, Lingshui Apr. Beijing, Beijing summer. Lingshui, Lingshui winter. Variable phenotypes of spikelets are defined as in S1 Table, and percentages of them in a panicle are shown in the y axis. le, lemma; pa, palea; st, stamen; eg, empty glume; if, inflorescence primordia; sp, smaller pa; lel, lemma-like organ; pl, palea-lemma mosaic organ. Bars = 2 mm. Values are means ± SE, number of analyzed panicles ≥ 5, and significant difference was determined by ANOVA, *P < 0.05, **P < 0.01.

Mentions: To further examine the influence of genotype on the floral plasticity of eg1, we swapped the genetic backgrounds of two eg1 alleles. eg1-1 in a largely japonica background showed high phenotypic plasticity especially for le and rs phenotypes, similar to eg1-2 (ZH11), whereas eg1-2 in an indica-dominant background showed low floral plasticity similar to eg1-1 (ZF802) (Fig 2A), indicating that genetic backgrounds also influence the phenotypic plasticity of eg1 spikelets.


A High Temperature-Dependent Mitochondrial Lipase EXTRA GLUME1 Promotes Floral Phenotypic Robustness against Temperature Fluctuation in Rice (Oryza sativa L.).

Zhang B, Wu S, Zhang Y, Xu T, Guo F, Tang H, Li X, Wang P, Qian W, Xue Y - PLoS Genet. (2016)

Subspecific variations of eg1 floral plasticity.(a) Floral plasticity of eg1 alleles in two exchanged backgrounds. eg1-1 (ZF802>ZH11) and eg1-2 (ZH11>ZF802) show eg1-1 and eg1-2 backcrossed into ZH11 or ZF802 backgrounds, respectively. (b) Floral plasticity of eg1-4 in indica Dular background. Statistical analysis of two types of panicles according to rs (Type I and Type II) are shown. (c) Floral plasticity of eg1-5 and -6 in japonica Nipponbare background. Statistical analysis of the two independent lines are shown. LS Feb, Lingshui Feb. LS Apr, Lingshui Apr. Beijing, Beijing summer. Lingshui, Lingshui winter. Variable phenotypes of spikelets are defined as in S1 Table, and percentages of them in a panicle are shown in the y axis. le, lemma; pa, palea; st, stamen; eg, empty glume; if, inflorescence primordia; sp, smaller pa; lel, lemma-like organ; pl, palea-lemma mosaic organ. Bars = 2 mm. Values are means ± SE, number of analyzed panicles ≥ 5, and significant difference was determined by ANOVA, *P < 0.05, **P < 0.01.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4930220&req=5

pgen.1006152.g002: Subspecific variations of eg1 floral plasticity.(a) Floral plasticity of eg1 alleles in two exchanged backgrounds. eg1-1 (ZF802>ZH11) and eg1-2 (ZH11>ZF802) show eg1-1 and eg1-2 backcrossed into ZH11 or ZF802 backgrounds, respectively. (b) Floral plasticity of eg1-4 in indica Dular background. Statistical analysis of two types of panicles according to rs (Type I and Type II) are shown. (c) Floral plasticity of eg1-5 and -6 in japonica Nipponbare background. Statistical analysis of the two independent lines are shown. LS Feb, Lingshui Feb. LS Apr, Lingshui Apr. Beijing, Beijing summer. Lingshui, Lingshui winter. Variable phenotypes of spikelets are defined as in S1 Table, and percentages of them in a panicle are shown in the y axis. le, lemma; pa, palea; st, stamen; eg, empty glume; if, inflorescence primordia; sp, smaller pa; lel, lemma-like organ; pl, palea-lemma mosaic organ. Bars = 2 mm. Values are means ± SE, number of analyzed panicles ≥ 5, and significant difference was determined by ANOVA, *P < 0.05, **P < 0.01.
Mentions: To further examine the influence of genotype on the floral plasticity of eg1, we swapped the genetic backgrounds of two eg1 alleles. eg1-1 in a largely japonica background showed high phenotypic plasticity especially for le and rs phenotypes, similar to eg1-2 (ZH11), whereas eg1-2 in an indica-dominant background showed low floral plasticity similar to eg1-1 (ZF802) (Fig 2A), indicating that genetic backgrounds also influence the phenotypic plasticity of eg1 spikelets.

Bottom Line: In this study, we found that eg1 (extra glume1) mutants of rice (Oryza savita L.) showed floral phenotypic variations in different growth locations resulting in a breakdown of floral identity robustness.Furthermore, we found that numerous environmentally responsive genes including many floral identity genes are transcriptionally repressed in eg1 mutants and OsMADS1, OsMADS6 and OsG1 genetically act downstream of EG1 to maintain floral robustness.Collectively, our results demonstrate that EG1 promotes floral robustness against temperature fluctuation by safeguarding the expression of floral identify genes through a high temperature-dependent mitochondrial lipid pathway and uncovers a novel mechanistic insight into floral developmental control.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences and National Center for Plant Gene Research, Beijing, the People's Republic of China.

ABSTRACT
The sessile plants have evolved diverse intrinsic mechanisms to control their proper development under variable environments. In contrast to plastic vegetative development, reproductive traits like floral identity often show phenotypic robustness against environmental variations. However, it remains obscure about the molecular basis of this phenotypic robustness. In this study, we found that eg1 (extra glume1) mutants of rice (Oryza savita L.) showed floral phenotypic variations in different growth locations resulting in a breakdown of floral identity robustness. Physiological and biochemical analyses showed that EG1 encodes a predominantly mitochondria-localized functional lipase and functions in a high temperature-dependent manner. Furthermore, we found that numerous environmentally responsive genes including many floral identity genes are transcriptionally repressed in eg1 mutants and OsMADS1, OsMADS6 and OsG1 genetically act downstream of EG1 to maintain floral robustness. Collectively, our results demonstrate that EG1 promotes floral robustness against temperature fluctuation by safeguarding the expression of floral identify genes through a high temperature-dependent mitochondrial lipid pathway and uncovers a novel mechanistic insight into floral developmental control.

No MeSH data available.


Related in: MedlinePlus