Limits...
BcMF26a and BcMF26b Are Duplicated Polygalacturonase Genes with Divergent Expression Patterns and Functions in Pollen Development and Pollen Tube Formation in Brassica campestris.

Lyu M, Yu Y, Jiang J, Song L, Liang Y, Ma Z, Xiong X, Cao J - PLoS ONE (2015)

Bottom Line: We found that these two genes were orthologous genes of At4g33440, and they originated from a chromosomal segmental duplication.Promoter activity analysis showed that, at reproductive development stages, BcMF26b promoter was active in tapetum, pollen grains, and pistils, whereas BcMF26a promoter was only active in pistils.In the subcellular localization experiment, BcMF26a and BcMF26b proteins could be localized to the cell wall.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Cell & Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Hangzhou, China.

ABSTRACT
Polygalacturonase (PG) is one of the cell wall hydrolytic enzymes involving in pectin degradation. A comparison of two highly conserved duplicated PG genes, namely, Brassica campestris Male Fertility 26a (BcMF26a) and BcMF26b, revealed the different features of their expression patterns and functions. We found that these two genes were orthologous genes of At4g33440, and they originated from a chromosomal segmental duplication. Although structurally similar, their regulatory and intron sequences largely diverged. QRT-PCR analysis showed that the expression level of BcMF26b was higher than that of BcMF26a in almost all the tested organs and tissues in Brassica campestris. Promoter activity analysis showed that, at reproductive development stages, BcMF26b promoter was active in tapetum, pollen grains, and pistils, whereas BcMF26a promoter was only active in pistils. In the subcellular localization experiment, BcMF26a and BcMF26b proteins could be localized to the cell wall. When the two genes were co-inhibited, pollen intine was formed abnormally and pollen tubes could not grow or stretch. Moreover, the knockout mutants of At4g33440 delayed the growth of pollen tubes. Therefore, BcMF26a/b can participate in the construction of pollen wall by modulating intine information and BcMF26b may play a major role in co-inhibiting transformed plants.

No MeSH data available.


Related in: MedlinePlus

Germination analysis of pollen grains in vitro in control and bcmf26a/b lines.(A and B) Morphological characterization of pollen germination. (A) Pollen tubes from control plants germinate normally. (B) The nonviable pollen grains of the bcmf26a/b lines could not germinate; the germinated pollen tubes of the bcmf26a/b lines exhibited two defective morphologies: pollen wall burst at the beginning of germination and pollen tube tip burst during the elongation process. Images of pollen tubes were obtained at 4 h after germination. Scale bars = 50 μm. (C) Comparison of pollen germination percentage between the pollen of bcmf26a/b and control plants. The percentage of normal pollen tube was only 27.7%–35.1% in the bcmf26a/b lines, but it was ~92.8% in the control. Standard errors are shown.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4495986&req=5

pone.0131173.g009: Germination analysis of pollen grains in vitro in control and bcmf26a/b lines.(A and B) Morphological characterization of pollen germination. (A) Pollen tubes from control plants germinate normally. (B) The nonviable pollen grains of the bcmf26a/b lines could not germinate; the germinated pollen tubes of the bcmf26a/b lines exhibited two defective morphologies: pollen wall burst at the beginning of germination and pollen tube tip burst during the elongation process. Images of pollen tubes were obtained at 4 h after germination. Scale bars = 50 μm. (C) Comparison of pollen germination percentage between the pollen of bcmf26a/b and control plants. The percentage of normal pollen tube was only 27.7%–35.1% in the bcmf26a/b lines, but it was ~92.8% in the control. Standard errors are shown.

Mentions: In vitro pollen germination analysis showed none of the germinated pollen tubes of the control pollen grains burst or displayed abnormal shapes after 4 h of incubation (Fig 9A). The germination rate was ~92.8% (Fig 9C). Whereas, in the bcmf26a/b lines (Fig 9B), the nonviable pollen grains could not germinate; the germinated abnormal pollen tubes exhibited two defective morphologies: pollen wall burst at the beginning of germination and pollen tube tip burst during the elongation process. The percentage of normal pollen tube was only 27.7% to 35.1% for the bcmf26a/b lines (Fig 9C).


BcMF26a and BcMF26b Are Duplicated Polygalacturonase Genes with Divergent Expression Patterns and Functions in Pollen Development and Pollen Tube Formation in Brassica campestris.

Lyu M, Yu Y, Jiang J, Song L, Liang Y, Ma Z, Xiong X, Cao J - PLoS ONE (2015)

Germination analysis of pollen grains in vitro in control and bcmf26a/b lines.(A and B) Morphological characterization of pollen germination. (A) Pollen tubes from control plants germinate normally. (B) The nonviable pollen grains of the bcmf26a/b lines could not germinate; the germinated pollen tubes of the bcmf26a/b lines exhibited two defective morphologies: pollen wall burst at the beginning of germination and pollen tube tip burst during the elongation process. Images of pollen tubes were obtained at 4 h after germination. Scale bars = 50 μm. (C) Comparison of pollen germination percentage between the pollen of bcmf26a/b and control plants. The percentage of normal pollen tube was only 27.7%–35.1% in the bcmf26a/b lines, but it was ~92.8% in the control. Standard errors are shown.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4495986&req=5

pone.0131173.g009: Germination analysis of pollen grains in vitro in control and bcmf26a/b lines.(A and B) Morphological characterization of pollen germination. (A) Pollen tubes from control plants germinate normally. (B) The nonviable pollen grains of the bcmf26a/b lines could not germinate; the germinated pollen tubes of the bcmf26a/b lines exhibited two defective morphologies: pollen wall burst at the beginning of germination and pollen tube tip burst during the elongation process. Images of pollen tubes were obtained at 4 h after germination. Scale bars = 50 μm. (C) Comparison of pollen germination percentage between the pollen of bcmf26a/b and control plants. The percentage of normal pollen tube was only 27.7%–35.1% in the bcmf26a/b lines, but it was ~92.8% in the control. Standard errors are shown.
Mentions: In vitro pollen germination analysis showed none of the germinated pollen tubes of the control pollen grains burst or displayed abnormal shapes after 4 h of incubation (Fig 9A). The germination rate was ~92.8% (Fig 9C). Whereas, in the bcmf26a/b lines (Fig 9B), the nonviable pollen grains could not germinate; the germinated abnormal pollen tubes exhibited two defective morphologies: pollen wall burst at the beginning of germination and pollen tube tip burst during the elongation process. The percentage of normal pollen tube was only 27.7% to 35.1% for the bcmf26a/b lines (Fig 9C).

Bottom Line: We found that these two genes were orthologous genes of At4g33440, and they originated from a chromosomal segmental duplication.Promoter activity analysis showed that, at reproductive development stages, BcMF26b promoter was active in tapetum, pollen grains, and pistils, whereas BcMF26a promoter was only active in pistils.In the subcellular localization experiment, BcMF26a and BcMF26b proteins could be localized to the cell wall.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Cell & Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Hangzhou, China.

ABSTRACT
Polygalacturonase (PG) is one of the cell wall hydrolytic enzymes involving in pectin degradation. A comparison of two highly conserved duplicated PG genes, namely, Brassica campestris Male Fertility 26a (BcMF26a) and BcMF26b, revealed the different features of their expression patterns and functions. We found that these two genes were orthologous genes of At4g33440, and they originated from a chromosomal segmental duplication. Although structurally similar, their regulatory and intron sequences largely diverged. QRT-PCR analysis showed that the expression level of BcMF26b was higher than that of BcMF26a in almost all the tested organs and tissues in Brassica campestris. Promoter activity analysis showed that, at reproductive development stages, BcMF26b promoter was active in tapetum, pollen grains, and pistils, whereas BcMF26a promoter was only active in pistils. In the subcellular localization experiment, BcMF26a and BcMF26b proteins could be localized to the cell wall. When the two genes were co-inhibited, pollen intine was formed abnormally and pollen tubes could not grow or stretch. Moreover, the knockout mutants of At4g33440 delayed the growth of pollen tubes. Therefore, BcMF26a/b can participate in the construction of pollen wall by modulating intine information and BcMF26b may play a major role in co-inhibiting transformed plants.

No MeSH data available.


Related in: MedlinePlus