Secondary xylem development has long been recognized as a typical case of programmed cell death （PCD） in plants. During PCD, the degradation of genomic DNA is catalyzed by endonucleases. However, to date, no endonuc...Secondary xylem development has long been recognized as a typical case of programmed cell death （PCD） in plants. During PCD, the degradation of genomic DNA is catalyzed by endonucleases. However, to date, no endonuclease has been shown to participate in secondary xylem development. Two novel Ca^2＋-dependent DNase genes, EuCaN1 and EuCaN2, were identified from the differentiating secondary xylem of the tree Eucommia ulmoides Oliv., their functions were studied by DNase activity assay, in situ hybridization, protein immunolocalization and virus-induced gene silencing experiments. Full-length cDNAs of EuCaN1 and EuCaN2 contained an open reading frame of 987 bp, encoding two proteins of 328 amino acids with SNase-like functional domains. The genomic DNA sequence for EuCaN1 had no introns, while EuCaN2 had 8 introns. EuCaN1 and EuCaN2 digested ssDNA and dsDNA with Ca^2＋-dependence at neutral pH. Their expression was confined to differentiating secondary xylem cells and the proteins were localized in the nucleus. Their activity dynamics was closely correlated with secondary xylem development. Secondary xylem cell differentiation is influenced by RNAi of endonuclease genes. The results provide evidence that the Ca^2＋-dependent DNases are involved in secondary xylem development.展开更多
Using the immuno-fluorescence and immuno-gold electron microscope technology, localization of ni- tric oxide synthase (NOS)-like proteins was determined in guard cells of Vicia faba L. NOS is mainly localized in nucle...Using the immuno-fluorescence and immuno-gold electron microscope technology, localization of ni- tric oxide synthase (NOS)-like proteins was determined in guard cells of Vicia faba L. NOS is mainly localized in nucleus, cytoplasm, chloroplast, mitochondria and the cell wall of guard cells. Scorch and exogenous JA can enhance the level of nitric oxide (NO) and increase NOS activity in both leaf and epidermis, and the changing pattern of NOS activity was consistent with the change of NO. NOS in- hibitor, L-NAME, inhibited JA-induced NO generation. From the results, we presumed that NO genera- tion from NOS pathway is the main pathway in the stress and JA responses. The pharmacological ex- periment showed that increasing the Ca2+ at a suitable concentration promoted leaf NOS activity and the NO level, indicating that NOS activity together with the distribution of NO is Ca2+-dependent. NOS and NO are possibly involved in the regulation of stomatal movement thus playing an important role in plant stress responses.展开更多
This brief article highlights the results of Fu et al.(Proc Natl Acad Sci USA 119:e2204574119,2022),who recently found that manganese(Mn)deficiency triggers long-lasting multicellular Ca^(2+) oscillations in the elong...This brief article highlights the results of Fu et al.(Proc Natl Acad Sci USA 119:e2204574119,2022),who recently found that manganese(Mn)deficiency triggers long-lasting multicellular Ca^(2+) oscillations in the elongation zone(EZ)of Arabidopsis roots and revealed a Ca^(2+)-CPK21/23-NRAMP1 axis as an important mechanism for plant tolerance and adaptation to low Mn.展开更多
The study aims to confirm the neuroregenerative effects of bacterial melanin （BM） on central nervous system injury using a special staining method based on the detection of Ca^2＋-dependent acid phosphatase activity...The study aims to confirm the neuroregenerative effects of bacterial melanin （BM） on central nervous system injury using a special staining method based on the detection of Ca^2＋-dependent acid phosphatase activity. Twenty-four rats were randomly assigned to undergo either unilateral destruction of sensorimotor cortex （group I; n = 12） or unilateral rubrospinal tract transection at the cervical level （C3-4） （group II; n = 12）. In each group, six rats were randomly selected after surgery to undergo intramuscular injection of BM solution （BM subgroup） and the remaining six rats were intramuscularly in）ected with saline （saline subgroup）. Neurological testing confirmed that BM accelerated the recovery of motor function in rats from both BM and saline subgroups. Two months after surgery, Ca^2＋-dependent acid phosphatase activity detection in combination with Chilingarian＇s calcium adenoside triphosphate method revealed that BM stimulated the sprouting of fibers and dilated the capillaries in the brain and spinal cord. These results suggest that BM can promote the recovery of motor function of rats with central nervous system injury; and detection of Ca^2＋-dependent acid phosphatase activity is a fast and easy method used to study the regeneration-promoting effects of BM on the injured central nervous system.展开更多
Transcription factors can be used to engineer plants for enhanced productivity.However,the mechanism(s)by which the C2H2-type zinc fi nger transcription factor enhances pathogen resistance in cells is not fully unders...Transcription factors can be used to engineer plants for enhanced productivity.However,the mechanism(s)by which the C2H2-type zinc fi nger transcription factor enhances pathogen resistance in cells is not fully understood.Here,Agrobacterium tumefaciens carrying the gene for Arabidopsis thaliana cysteine2/histidine2-type transcription factor 6(ZAT6)was used to engineer rice(Oryza sativa L.),cotton(Gossypium hirsutum L.),and slash pine(Pinus elliottii Engelm.)to generate transgenic cell lines.Transgenic cells were then inoculated with the pathogenic bacterium Pseudomonas syringae.Compared to the control,cell viability of transgenic cells increased 39–47%and growth rate increased 9–15%by 7 days after inoculation in rice,cotton and slash pine.Acid phosphatase activity and alkaline phosphatase activity and transcript levels of Ca 2+-dependent protein kinase genes OsCPK1,OsCPK2,OsCPK6,and OsCPK8 and mitogen-activated protein kinase genes OsMAPK1,OsMAPK2,OsMAPK3,and OsMAPK8 increased signifi cantly in transgenic rice cells by 3 day after inoculation,and extracellular pH had decreased by 10–14%by 96 min after inoculation in transgenic rice,cotton and slash pine cells.These results suggest that ZAT6 enhances P.syringae resistance in plant cells by modulating transcription of CPK and MAPK and oxidase activity.展开更多
基金supported by the National Basic Research Program of China (2012CB114500)the National Natural Science Foundation of China (31070156)
文摘Secondary xylem development has long been recognized as a typical case of programmed cell death （PCD） in plants. During PCD, the degradation of genomic DNA is catalyzed by endonucleases. However, to date, no endonuclease has been shown to participate in secondary xylem development. Two novel Ca^2＋-dependent DNase genes, EuCaN1 and EuCaN2, were identified from the differentiating secondary xylem of the tree Eucommia ulmoides Oliv., their functions were studied by DNase activity assay, in situ hybridization, protein immunolocalization and virus-induced gene silencing experiments. Full-length cDNAs of EuCaN1 and EuCaN2 contained an open reading frame of 987 bp, encoding two proteins of 328 amino acids with SNase-like functional domains. The genomic DNA sequence for EuCaN1 had no introns, while EuCaN2 had 8 introns. EuCaN1 and EuCaN2 digested ssDNA and dsDNA with Ca^2＋-dependence at neutral pH. Their expression was confined to differentiating secondary xylem cells and the proteins were localized in the nucleus. Their activity dynamics was closely correlated with secondary xylem development. Secondary xylem cell differentiation is influenced by RNAi of endonuclease genes. The results provide evidence that the Ca^2＋-dependent DNases are involved in secondary xylem development.
基金Supported by the National Natural Science Foundation of China (Grant No. 30370141)
文摘Using the immuno-fluorescence and immuno-gold electron microscope technology, localization of ni- tric oxide synthase (NOS)-like proteins was determined in guard cells of Vicia faba L. NOS is mainly localized in nucleus, cytoplasm, chloroplast, mitochondria and the cell wall of guard cells. Scorch and exogenous JA can enhance the level of nitric oxide (NO) and increase NOS activity in both leaf and epidermis, and the changing pattern of NOS activity was consistent with the change of NO. NOS in- hibitor, L-NAME, inhibited JA-induced NO generation. From the results, we presumed that NO genera- tion from NOS pathway is the main pathway in the stress and JA responses. The pharmacological ex- periment showed that increasing the Ca2+ at a suitable concentration promoted leaf NOS activity and the NO level, indicating that NOS activity together with the distribution of NO is Ca2+-dependent. NOS and NO are possibly involved in the regulation of stomatal movement thus playing an important role in plant stress responses.
基金supported by grants from National Natural Science Foundation of China(Grant No.31900216)National Key Laboratory of Plant Molecular Genetics.
文摘This brief article highlights the results of Fu et al.(Proc Natl Acad Sci USA 119:e2204574119,2022),who recently found that manganese(Mn)deficiency triggers long-lasting multicellular Ca^(2+) oscillations in the elongation zone(EZ)of Arabidopsis roots and revealed a Ca^(2+)-CPK21/23-NRAMP1 axis as an important mechanism for plant tolerance and adaptation to low Mn.
基金supported by the Armenian National Science and Education Fund for Project in New York,USA(No.ANSEF biotech-4241)
文摘The study aims to confirm the neuroregenerative effects of bacterial melanin （BM） on central nervous system injury using a special staining method based on the detection of Ca^2＋-dependent acid phosphatase activity. Twenty-four rats were randomly assigned to undergo either unilateral destruction of sensorimotor cortex （group I; n = 12） or unilateral rubrospinal tract transection at the cervical level （C3-4） （group II; n = 12）. In each group, six rats were randomly selected after surgery to undergo intramuscular injection of BM solution （BM subgroup） and the remaining six rats were intramuscularly in）ected with saline （saline subgroup）. Neurological testing confirmed that BM accelerated the recovery of motor function in rats from both BM and saline subgroups. Two months after surgery, Ca^2＋-dependent acid phosphatase activity detection in combination with Chilingarian＇s calcium adenoside triphosphate method revealed that BM stimulated the sprouting of fibers and dilated the capillaries in the brain and spinal cord. These results suggest that BM can promote the recovery of motor function of rats with central nervous system injury; and detection of Ca^2＋-dependent acid phosphatase activity is a fast and easy method used to study the regeneration-promoting effects of BM on the injured central nervous system.
文摘Transcription factors can be used to engineer plants for enhanced productivity.However,the mechanism(s)by which the C2H2-type zinc fi nger transcription factor enhances pathogen resistance in cells is not fully understood.Here,Agrobacterium tumefaciens carrying the gene for Arabidopsis thaliana cysteine2/histidine2-type transcription factor 6(ZAT6)was used to engineer rice(Oryza sativa L.),cotton(Gossypium hirsutum L.),and slash pine(Pinus elliottii Engelm.)to generate transgenic cell lines.Transgenic cells were then inoculated with the pathogenic bacterium Pseudomonas syringae.Compared to the control,cell viability of transgenic cells increased 39–47%and growth rate increased 9–15%by 7 days after inoculation in rice,cotton and slash pine.Acid phosphatase activity and alkaline phosphatase activity and transcript levels of Ca 2+-dependent protein kinase genes OsCPK1,OsCPK2,OsCPK6,and OsCPK8 and mitogen-activated protein kinase genes OsMAPK1,OsMAPK2,OsMAPK3,and OsMAPK8 increased signifi cantly in transgenic rice cells by 3 day after inoculation,and extracellular pH had decreased by 10–14%by 96 min after inoculation in transgenic rice,cotton and slash pine cells.These results suggest that ZAT6 enhances P.syringae resistance in plant cells by modulating transcription of CPK and MAPK and oxidase activity.
基金This work was supported partially by the National Natural Science Foundation of China (No. 30070809 30371525) National Science Fund for Distinguished Scholars (No. 39925035).
