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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

Temperature-dependent floral plasticity of eg1.(a) Floral plasticity of eg1-1 (ZF802) under two different temperature conditions. (b) Floral plasticity of eg1-2 (ZH11) under two different temperature conditions. Spikelet phenotypes and statistical analysis are shown in the left and right of (a) and (b). Variable phenotypes of spikelets are defined as in S1 Table. le, lemma; pa, palea; eg, empty glume; if, inflorescence primordia; lel, lemma-like organ; pl, palea-lemma mosaic organ; leg, long empty glume in spikelet structures. Bars = 2 mm. Values are means ± SE, number of analyzed panicles >10, and significant difference was determined by ANOVA, *P < 0.05, **P < 0.01.
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pgen.1006152.g003: Temperature-dependent floral plasticity of eg1.(a) Floral plasticity of eg1-1 (ZF802) under two different temperature conditions. (b) Floral plasticity of eg1-2 (ZH11) under two different temperature conditions. Spikelet phenotypes and statistical analysis are shown in the left and right of (a) and (b). Variable phenotypes of spikelets are defined as in S1 Table. le, lemma; pa, palea; eg, empty glume; if, inflorescence primordia; lel, lemma-like organ; pl, palea-lemma mosaic organ; leg, long empty glume in spikelet structures. Bars = 2 mm. Values are means ± SE, number of analyzed panicles >10, and significant difference was determined by ANOVA, *P < 0.05, **P < 0.01.

Mentions: In order to find out the environmental factors mediating the plastic development of eg1 spikelets, we first compared the growing conditions for phenotypic analysis and found a marked difference in daily high temperatures of two environments (S4 Fig), suggesting that the temperature variation between two environments could be a major environmental factor influencing the eg1 plasticity. To verify this prediction, floral plasticity of wild-types and eg1 alleles were examined in two artificial growth chambers with 35°C light 12 hr / 20°C dark 12 hr and 25°C light 12 hr / 20°C dark 12 hr respectively, while other growth conditions were kept identical. The low plasticity of eg1-1 and nearly 70% le phenotypes of eg1-2 showed that the floral plasticity of eg1 in the chambers was similar to and even higher than that under natural growth conditions (Fig 3). These results showed that temperature is a major environmental factor mediating the floral plasticity of eg1.


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)

Temperature-dependent floral plasticity of eg1.(a) Floral plasticity of eg1-1 (ZF802) under two different temperature conditions. (b) Floral plasticity of eg1-2 (ZH11) under two different temperature conditions. Spikelet phenotypes and statistical analysis are shown in the left and right of (a) and (b). Variable phenotypes of spikelets are defined as in S1 Table. le, lemma; pa, palea; eg, empty glume; if, inflorescence primordia; lel, lemma-like organ; pl, palea-lemma mosaic organ; leg, long empty glume in spikelet structures. Bars = 2 mm. Values are means ± SE, number of analyzed panicles >10, 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.g003: Temperature-dependent floral plasticity of eg1.(a) Floral plasticity of eg1-1 (ZF802) under two different temperature conditions. (b) Floral plasticity of eg1-2 (ZH11) under two different temperature conditions. Spikelet phenotypes and statistical analysis are shown in the left and right of (a) and (b). Variable phenotypes of spikelets are defined as in S1 Table. le, lemma; pa, palea; eg, empty glume; if, inflorescence primordia; lel, lemma-like organ; pl, palea-lemma mosaic organ; leg, long empty glume in spikelet structures. Bars = 2 mm. Values are means ± SE, number of analyzed panicles >10, and significant difference was determined by ANOVA, *P < 0.05, **P < 0.01.
Mentions: In order to find out the environmental factors mediating the plastic development of eg1 spikelets, we first compared the growing conditions for phenotypic analysis and found a marked difference in daily high temperatures of two environments (S4 Fig), suggesting that the temperature variation between two environments could be a major environmental factor influencing the eg1 plasticity. To verify this prediction, floral plasticity of wild-types and eg1 alleles were examined in two artificial growth chambers with 35°C light 12 hr / 20°C dark 12 hr and 25°C light 12 hr / 20°C dark 12 hr respectively, while other growth conditions were kept identical. The low plasticity of eg1-1 and nearly 70% le phenotypes of eg1-2 showed that the floral plasticity of eg1 in the chambers was similar to and even higher than that under natural growth conditions (Fig 3). These results showed that temperature is a major environmental factor mediating the floral plasticity of eg1.

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