Abstract
MicroRNA399 (miR399) regulates phosphate homeostasis in plants by down-regulating the expression of PHOSPHATE2 (PHO2, or UBC24 encoding the ubiquitin-conjugating E2 enzyme). We previously identified CsmiR399a.1 in a small RNA sequencing screen of a male-sterile somatic cytoplasmic hybrid (or cybrid) of pummelo (Citrus grandis). Here, we report that miR399 affects reproductive development and male fertility in citrus. Down-regulation of CsmiR399a.1 using a short tandem target mimic (STTM) led to abnormal floral development, inhibition of anther dehiscence, and decreased pollen fertility. When grown in inorganic phosphate (Pi)-sufficient conditions, CsmiR399a.1-STTM plants had lower total phosphorus content in their leaves than the wild type and showed typical symptoms of Pi deficiency. In CsmiR399a.1-STTM plants, the expression of genes involved in starch metabolism and Pi homeostasis was significantly different than in the wild type. Thus, we conclude that miR399-STTM mimicked Pi deficiency, disturbed starch metabolism, and was responsible for pollen grain collapse in the transgenic lines. We identified CsUBC24, a citrus homolog of Arabidopsis (Arabidopsis thaliana) AtUBC24 (PHO2), as a target of CsmiR399a.1 that physically interacts with the floral development regulators SEPALLATA family (CsSEP1.1, CsSEP1.2, and CsSEP3) and the anther dehiscence regulator INDUCER OF CBF EXPRESSION1 (CsICE1). We hypothesize that CsUBC24 downregulates the CsSEPs, which disrupts the floral meristem identity regulatory network and leads to developmental abnormalities in flowers. By interacting with CsICE1, CsUBC24 disturbs stomate function on the anther surface, which inhibits anther dehiscence. These findings indicate that a miR399-based mechanism influences both reproductive development and male fertility in citrus.
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Claims 12
Claim · model-written summary
Suppressing CsmiR399a.1 caused abnormal floral development.
- Treatment
- Down-regulation of CsmiR399a.1 using a short tandem target mimic (STTM)e0
- Gene
- CsmiR399a.1e0
- Outcome
- abnormal floral developmente0
CitrusNot reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Down-regulation of CsmiR399a.1 using a short tandem target mimic (STTM) led to abnormal floral development”
t0“Citrus”
Claim · model-written summary
Suppressing CsmiR399a.1 inhibited anther dehiscence.
- Treatment
- Down-regulation of CsmiR399a.1 using a short tandem target mimic (STTM)e0
- Gene
- CsmiR399a.1e0
- Outcome
- anther dehiscencee0
- Direction
- inhibitione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Down-regulation of CsmiR399a.1 using a short tandem target mimic (STTM) led to abnormal floral development, inhibition of anther dehiscence”
t0“Citrus”
Claim · model-written summary
Suppressing CsmiR399a.1 decreased pollen fertility.
- Treatment
- Down-regulation of CsmiR399a.1 using a short tandem target mimic (STTM)e0
- Gene
- CsmiR399a.1e0
- Outcome
- pollen fertilitye0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Down-regulation of CsmiR399a.1 using a short tandem target mimic (STTM) led to abnormal floral development, inhibition of anther dehiscence, and decreased pollen fertility”
t0“Citrus”
Claim · model-written summary
Under sufficient phosphate, CsmiR399a.1-STTM plants had less leaf phosphorus than wild type.
- Organ / stage
- leavese0
- Treatment
- CsmiR399a.1-STTMe0
- Outcome
- total phosphorus contente0
- Direction
- lowere0
- Qualifier
- inorganic phosphate (Pi)-sufficient conditionse0
- Comparator
- wild typee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When grown in inorganic phosphate (Pi)-sufficient conditions, CsmiR399a.1-STTM plants had lower total phosphorus content in their leaves than the wild type”
t0“Citrus”
Claim · model-written summary
CsmiR399a.1-STTM plants showed phosphate deficiency symptoms.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“CsmiR399a.1-STTM plants had lower total phosphorus content in their leaves than the wild type and showed typical symptoms of Pi deficiency”
t0“Citrus”
Claim · model-written summary
Starch metabolism and phosphate homeostasis gene expression differed in CsmiR399a.1-STTM plants versus wild type.
- Material
- CsmiR399a.1-STTM plantse0
- Outcome
- expression of genes involved in starch metabolism and Pi homeostasise0
- Comparator
- wild typee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In CsmiR399a.1-STTM plants, the expression of genes involved in starch metabolism and Pi homeostasis was significantly different than in the wild type”
t0“Citrus”
Claim · model-written summary
Authors attribute pollen grain collapse in transgenic lines to mimicked phosphate deficiency and disturbed starch metabolism.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“miR399-STTM mimicked Pi deficiency, disturbed starch metabolism, and was responsible for pollen grain collapse in the transgenic lines”
t0“Citrus”
Claim · model-written summary
CsUBC24 was identified as a target of CsmiR399a.1.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We identified CsUBC24, a citrus homolog of Arabidopsis (Arabidopsis thaliana) AtUBC24 (PHO2), as a target of CsmiR399a.1”
t0“Citrus”
Claim · model-written summary
CsUBC24 physically interacts with CsSEP1.1, CsSEP1.2 and CsSEP3.
- Gene
- CsUBC24e0
- Outcome
- physically interacts with the floral development regulators SEPALLATA family (CsSEP1.1, CsSEP1.2, and CsSEP3)e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“CsUBC24, a citrus homolog of Arabidopsis (Arabidopsis thaliana) AtUBC24 (PHO2), as a target of CsmiR399a.1 that physically interacts with the floral development regulators SEPALLATA family (CsSEP1.1, CsSEP1.2, and CsSEP3)”
t0“Citrus”
Claim · model-written summary
CsUBC24 physically interacts with CsICE1.
- Gene
- CsUBC24e0
- Outcome
- physically interacts with the floral development regulators SEPALLATA family (CsSEP1.1, CsSEP1.2, and CsSEP3) and the anther dehiscence regulator INDUCER OF CBF EXPRESSION1 (CsICE1)e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“CsUBC24, a citrus homolog of Arabidopsis (Arabidopsis thaliana) AtUBC24 (PHO2), as a target of CsmiR399a.1 that physically interacts with the floral development regulators SEPALLATA family (CsSEP1.1, CsSEP1.2, and CsSEP3) and the anther dehiscence regulator INDUCER OF CBF EXPRESSION1 (CsICE1)”
t0“Citrus”
Claim · model-written summary
The authors hypothesize that CsUBC24 downregulates CsSEPs, disrupting floral meristem identity and flower development.
- Gene
- CsUBC24e0
- Outcome
- developmental abnormalities in flowerse0
- Qualifier
- disrupts the floral meristem identity regulatory networke0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“CsUBC24 downregulates the CsSEPs, which disrupts the floral meristem identity regulatory network and leads to developmental abnormalities in flowers”
t0“Citrus”
Claim · model-written summary
The authors propose that CsUBC24 interaction with CsICE1 impairs anther stomata and dehiscence.
- Gene
- CsUBC24e0
- Outcome
- anther dehiscencee0
- Direction
- inhibitse0
- Qualifier
- disturbs stomate function on the anther surfacee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“By interacting with CsICE1, CsUBC24 disturbs stomate function on the anther surface, which inhibits anther dehiscence”
t0“Citrus”
The same questions in other papers
loss of function · growth · CitrusPositive and negative results
3 papers in the same direction as this paper · 2 in the opposite direction
- positive
- negative
- positive
2 papers more in this group
See all 6 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.