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The cold responsive mechanism of the paper mulberry: decreased photosynthesis capacity and increased starch accumulation.

Peng X, Teng L, Yan X, Zhao M, Shen S - BMC Genomics (2015)

Bottom Line: For screening of differentially expressed genes, the expression level of every transcript in each sample was calculated by quantifying the number of Illumina reads.Finally, real time PCR was used to verify the DEG results of the RNA-seq and the proteomics data.Total of 5800 unigenes and 38 proteins were affected, including the repressed expression of photosynthesis and the enhanced expression in signal transduction, stress defense pathway as well as secondary metabolism.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China. pengxianjun@ibcas.ac.cn.

ABSTRACT

Background: Most studies on the paper mulberry are mainly focused on the medicated and pharmacology, fiber quality, leaves feed development, little is known about its mechanism of adaptability to abiotic stress. Physiological measurement, transcriptomics and proteomic analysis were employed to understand its response to cold stress in this study.

Methods: The second to fourth fully expanded leaves from up to down were harvested at different stress time points forthe transmission electron microscope (TEM) observation. Physiological characteristics measurement included the relative electrolyte leakage (REL), SOD activity assay, soluble sugar content, and Chlorophyll fluorescence parameter measurement. For screening of differentially expressed genes, the expression level of every transcript in each sample was calculated by quantifying the number of Illumina reads. To identify the differentially expressed protein, leaves of plants under 0, 6, 12, 24, 48 and 72 h cold stress wereharvested for proteomic analysis. Finally, real time PCR was used to verify the DEG results of the RNA-seq and the proteomics data.

Results: Results showed that at the beginning of cold stress, respiratory metabolism was decreased and the transportation and hydrolysis of photosynthetic products was inhibited, leading to an accumulation of starch in the chloroplasts. Total of 5800 unigenes and 38 proteins were affected, including the repressed expression of photosynthesis and the enhanced expression in signal transduction, stress defense pathway as well as secondary metabolism. Although the transcriptional level of a large number of genes has been restored after 12 h, sustained cold stress brought more serious injury to the leaf cells, including the sharp rise of the relative electrolyte leakage, the declined Fv/Fm value, swelled chloroplast and the disintegrated membrane system.

Conclusion: The starch accumulation and the photoinhibition might be the main adaptive mechanism of the paper mulberry responded to cold stress. Most of important, enhancing the transport and hydrolysis of photosynthetic products could be the potential targets for improving the cold tolerance of the paper mulberry.

No MeSH data available.


Related in: MedlinePlus

The exhibition of the Physiological process under normal condition and cold stress. Under normal condition, there was a dynamic equilibrium between starch syntheses and transformation into triose phosphate from the photosynthesis product. The sustained cold stress led to the photoinhibition, which affected the synthesis of the sucrose and these conversely led to the accumulation of the starch in the chloroplast. The dashed was used to illustrate the slower physical process and the inverted T-shaped line showed the repressed physical process. Double dotted line showed that the dynamic equilibrium of the triose phosphate transportation and the sucrose synthesis had been broken
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Fig7: The exhibition of the Physiological process under normal condition and cold stress. Under normal condition, there was a dynamic equilibrium between starch syntheses and transformation into triose phosphate from the photosynthesis product. The sustained cold stress led to the photoinhibition, which affected the synthesis of the sucrose and these conversely led to the accumulation of the starch in the chloroplast. The dashed was used to illustrate the slower physical process and the inverted T-shaped line showed the repressed physical process. Double dotted line showed that the dynamic equilibrium of the triose phosphate transportation and the sucrose synthesis had been broken

Mentions: Under normal condition, starch was synthesized in the chloroplast and then is catalyzed into triose phosphate which was transported out and used for the synthesis of the sucrose. TCA cycles supply the ATP for these processes. During cold stress, the photorespiration were repressed, which affected the transportation of triose phosphate and the synthesis of the sucrose and these conversely led to the accumulation of the starch in the chloroplast though the synthesis rate of starch were slower caused by the photoinhibition under cold stress (Fig. 7).Fig. 7


The cold responsive mechanism of the paper mulberry: decreased photosynthesis capacity and increased starch accumulation.

Peng X, Teng L, Yan X, Zhao M, Shen S - BMC Genomics (2015)

The exhibition of the Physiological process under normal condition and cold stress. Under normal condition, there was a dynamic equilibrium between starch syntheses and transformation into triose phosphate from the photosynthesis product. The sustained cold stress led to the photoinhibition, which affected the synthesis of the sucrose and these conversely led to the accumulation of the starch in the chloroplast. The dashed was used to illustrate the slower physical process and the inverted T-shaped line showed the repressed physical process. Double dotted line showed that the dynamic equilibrium of the triose phosphate transportation and the sucrose synthesis had been broken
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4634900&req=5

Fig7: The exhibition of the Physiological process under normal condition and cold stress. Under normal condition, there was a dynamic equilibrium between starch syntheses and transformation into triose phosphate from the photosynthesis product. The sustained cold stress led to the photoinhibition, which affected the synthesis of the sucrose and these conversely led to the accumulation of the starch in the chloroplast. The dashed was used to illustrate the slower physical process and the inverted T-shaped line showed the repressed physical process. Double dotted line showed that the dynamic equilibrium of the triose phosphate transportation and the sucrose synthesis had been broken
Mentions: Under normal condition, starch was synthesized in the chloroplast and then is catalyzed into triose phosphate which was transported out and used for the synthesis of the sucrose. TCA cycles supply the ATP for these processes. During cold stress, the photorespiration were repressed, which affected the transportation of triose phosphate and the synthesis of the sucrose and these conversely led to the accumulation of the starch in the chloroplast though the synthesis rate of starch were slower caused by the photoinhibition under cold stress (Fig. 7).Fig. 7

Bottom Line: For screening of differentially expressed genes, the expression level of every transcript in each sample was calculated by quantifying the number of Illumina reads.Finally, real time PCR was used to verify the DEG results of the RNA-seq and the proteomics data.Total of 5800 unigenes and 38 proteins were affected, including the repressed expression of photosynthesis and the enhanced expression in signal transduction, stress defense pathway as well as secondary metabolism.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China. pengxianjun@ibcas.ac.cn.

ABSTRACT

Background: Most studies on the paper mulberry are mainly focused on the medicated and pharmacology, fiber quality, leaves feed development, little is known about its mechanism of adaptability to abiotic stress. Physiological measurement, transcriptomics and proteomic analysis were employed to understand its response to cold stress in this study.

Methods: The second to fourth fully expanded leaves from up to down were harvested at different stress time points forthe transmission electron microscope (TEM) observation. Physiological characteristics measurement included the relative electrolyte leakage (REL), SOD activity assay, soluble sugar content, and Chlorophyll fluorescence parameter measurement. For screening of differentially expressed genes, the expression level of every transcript in each sample was calculated by quantifying the number of Illumina reads. To identify the differentially expressed protein, leaves of plants under 0, 6, 12, 24, 48 and 72 h cold stress wereharvested for proteomic analysis. Finally, real time PCR was used to verify the DEG results of the RNA-seq and the proteomics data.

Results: Results showed that at the beginning of cold stress, respiratory metabolism was decreased and the transportation and hydrolysis of photosynthetic products was inhibited, leading to an accumulation of starch in the chloroplasts. Total of 5800 unigenes and 38 proteins were affected, including the repressed expression of photosynthesis and the enhanced expression in signal transduction, stress defense pathway as well as secondary metabolism. Although the transcriptional level of a large number of genes has been restored after 12 h, sustained cold stress brought more serious injury to the leaf cells, including the sharp rise of the relative electrolyte leakage, the declined Fv/Fm value, swelled chloroplast and the disintegrated membrane system.

Conclusion: The starch accumulation and the photoinhibition might be the main adaptive mechanism of the paper mulberry responded to cold stress. Most of important, enhancing the transport and hydrolysis of photosynthetic products could be the potential targets for improving the cold tolerance of the paper mulberry.

No MeSH data available.


Related in: MedlinePlus