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Impacts of strigolactone on shoot branching under phosphate starvation in chrysanthemum (Dendranthema grandiflorum cv. Jinba).

Xi L, Wen C, Fang S, Chen X, Nie J, Chu J, Yuan C, Yan C, Ma N, Zhao L - Front Plant Sci (2015)

Bottom Line: Here, we demonstrated that phosphorus (Pi) starvation significantly reduces axillary bud outgrowth in chrysanthemum.Treatment of node segments with or without auxin and Pi revealed that in the absence of exogenous auxin, Pi delayed axillary buds outgrowth and up-regulated local SL pathway genes.We proposed that SLs contributed to chrysanthemum shoot branching control in response to Pi-limiting conditions in a systemic way.

View Article: PubMed Central - PubMed

Affiliation: Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University Beijing, China.

ABSTRACT
Chrysanthemum (Dendranthema grandiflorum cv. Jinba) shoot branching is determined by bud outgrowth during the vegetative growth stage. The degree of axillary bud outgrowth is highly influenced by environmental conditions, such as nutrient availability. Here, we demonstrated that phosphorus (Pi) starvation significantly reduces axillary bud outgrowth in chrysanthemum. A strigolactone (SL) biosynthesis gene, DgCCD7, was isolated and characterized as an ortholog of MAX3/DAD3/RMS5/D17. By using ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS), three putative SLs were identified and levels of all three SLs showed strong increase under Pi starvation conditions. Determinations of the distribution of SLs and regulation of DgCCD7/8 in response to Pi changes in root indicate that SL acts systemically. However, temporal expression patterns of biosynthesis and signaling genes in nodes revealed that Pi starvation causes a local response of SL pathway. Treatment of node segments with or without auxin and Pi revealed that in the absence of exogenous auxin, Pi delayed axillary buds outgrowth and up-regulated local SL pathway genes. These data indicated that an auxin-SL regulatory loop responded to Pi starvation for delaying bud outgrowth locally, root biosynthesized SLs were transported acropetally and functioned in shoot branching inhibition under Pi starvation. We proposed that SLs contributed to chrysanthemum shoot branching control in response to Pi-limiting conditions in a systemic way.

No MeSH data available.


Related in: MedlinePlus

Quantification of putative SL analogs in root exudates and whole chrysanthemum plant. (A) SL analog levels in root exudates. N.D. not detected due to low abundance. (B) SL analog distribution levels in chrysanthemum. N.D. not detected due to low abundance. Means ± SE of three biological replicates are shown. Each replicates contains 60–100 plants. Comparison between Pi starvation (Pi−) and Pi sufficient (Pi+) conditions using Student's t-test; **P < 0.01. SB, bottom parts of stems; SU, upper parts of stems; R, root.
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Figure 3: Quantification of putative SL analogs in root exudates and whole chrysanthemum plant. (A) SL analog levels in root exudates. N.D. not detected due to low abundance. (B) SL analog distribution levels in chrysanthemum. N.D. not detected due to low abundance. Means ± SE of three biological replicates are shown. Each replicates contains 60–100 plants. Comparison between Pi starvation (Pi−) and Pi sufficient (Pi+) conditions using Student's t-test; **P < 0.01. SB, bottom parts of stems; SU, upper parts of stems; R, root.

Mentions: To evaluate the relationship between Pi starvation and SL analog accumulation in chrysanthemum root exudate, the three compounds were quantified under hydroponic culture conditions of full fertilization and Pi starvation (Yoneyama et al., 2012). Exudation of all three analogs increased significantly in the Pi-depleted culture system after 2 weeks, compared with that in fully fertilized conditions. Compounds 361 (p = 7.53E-09) and 377 (p = 1.87E-05) were rarely detected in root exudates under full nutrient cultivation conditions (Figure 3A). The finding that Pi starvation induces SL analog accumulation in root exudates of chrysanthemum is consistent with earlier data obtained using different plant species (López-Ráez et al., 2008; Umehara et al., 2010; Yoneyama et al., 2012). In combination with the results obtained from a variety of plants, these Pi induction experiments confirmed that the three components are novel putative SLs in chrysanthemum.


Impacts of strigolactone on shoot branching under phosphate starvation in chrysanthemum (Dendranthema grandiflorum cv. Jinba).

Xi L, Wen C, Fang S, Chen X, Nie J, Chu J, Yuan C, Yan C, Ma N, Zhao L - Front Plant Sci (2015)

Quantification of putative SL analogs in root exudates and whole chrysanthemum plant. (A) SL analog levels in root exudates. N.D. not detected due to low abundance. (B) SL analog distribution levels in chrysanthemum. N.D. not detected due to low abundance. Means ± SE of three biological replicates are shown. Each replicates contains 60–100 plants. Comparison between Pi starvation (Pi−) and Pi sufficient (Pi+) conditions using Student's t-test; **P < 0.01. SB, bottom parts of stems; SU, upper parts of stems; R, root.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4566059&req=5

Figure 3: Quantification of putative SL analogs in root exudates and whole chrysanthemum plant. (A) SL analog levels in root exudates. N.D. not detected due to low abundance. (B) SL analog distribution levels in chrysanthemum. N.D. not detected due to low abundance. Means ± SE of three biological replicates are shown. Each replicates contains 60–100 plants. Comparison between Pi starvation (Pi−) and Pi sufficient (Pi+) conditions using Student's t-test; **P < 0.01. SB, bottom parts of stems; SU, upper parts of stems; R, root.
Mentions: To evaluate the relationship between Pi starvation and SL analog accumulation in chrysanthemum root exudate, the three compounds were quantified under hydroponic culture conditions of full fertilization and Pi starvation (Yoneyama et al., 2012). Exudation of all three analogs increased significantly in the Pi-depleted culture system after 2 weeks, compared with that in fully fertilized conditions. Compounds 361 (p = 7.53E-09) and 377 (p = 1.87E-05) were rarely detected in root exudates under full nutrient cultivation conditions (Figure 3A). The finding that Pi starvation induces SL analog accumulation in root exudates of chrysanthemum is consistent with earlier data obtained using different plant species (López-Ráez et al., 2008; Umehara et al., 2010; Yoneyama et al., 2012). In combination with the results obtained from a variety of plants, these Pi induction experiments confirmed that the three components are novel putative SLs in chrysanthemum.

Bottom Line: Here, we demonstrated that phosphorus (Pi) starvation significantly reduces axillary bud outgrowth in chrysanthemum.Treatment of node segments with or without auxin and Pi revealed that in the absence of exogenous auxin, Pi delayed axillary buds outgrowth and up-regulated local SL pathway genes.We proposed that SLs contributed to chrysanthemum shoot branching control in response to Pi-limiting conditions in a systemic way.

View Article: PubMed Central - PubMed

Affiliation: Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University Beijing, China.

ABSTRACT
Chrysanthemum (Dendranthema grandiflorum cv. Jinba) shoot branching is determined by bud outgrowth during the vegetative growth stage. The degree of axillary bud outgrowth is highly influenced by environmental conditions, such as nutrient availability. Here, we demonstrated that phosphorus (Pi) starvation significantly reduces axillary bud outgrowth in chrysanthemum. A strigolactone (SL) biosynthesis gene, DgCCD7, was isolated and characterized as an ortholog of MAX3/DAD3/RMS5/D17. By using ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS), three putative SLs were identified and levels of all three SLs showed strong increase under Pi starvation conditions. Determinations of the distribution of SLs and regulation of DgCCD7/8 in response to Pi changes in root indicate that SL acts systemically. However, temporal expression patterns of biosynthesis and signaling genes in nodes revealed that Pi starvation causes a local response of SL pathway. Treatment of node segments with or without auxin and Pi revealed that in the absence of exogenous auxin, Pi delayed axillary buds outgrowth and up-regulated local SL pathway genes. These data indicated that an auxin-SL regulatory loop responded to Pi starvation for delaying bud outgrowth locally, root biosynthesized SLs were transported acropetally and functioned in shoot branching inhibition under Pi starvation. We proposed that SLs contributed to chrysanthemum shoot branching control in response to Pi-limiting conditions in a systemic way.

No MeSH data available.


Related in: MedlinePlus