Tissue culture has been widely used for mass propagation of Phalaenopsis. However, somaclonal variation occurred during micropropagation process posed a severe problem by affecting product quality. In this study, wild...Tissue culture has been widely used for mass propagation of Phalaenopsis. However, somaclonal variation occurred during micropropagation process posed a severe problem by affecting product quality. In this study, wild type and peloric flower buds of Phalaenopsis hybrids derived from flower stalk nodal culture were used for cDNA-RAPD and cDNA suppression subtractive hybridization analyses in order to study their genetic difference in terms of expressed sequence tags. A total of 209 ESTs from normal flower buds and 230 from mutants were sequenced. These ESTs sequences can be grouped into several functional categories involved in different cellular processes including metabolism, signal transduction, transcription, cell growth and division, protein synthesis, and protein localization, and into a subcat- egory of proteins with unknown function. Cymbidium mosaic virus transcript was surprisingly found expressed fre- quently in the peloric mutant of P. Little Mary. Real-time RT-PCR analysis on selected ESTs showed that in mutant flower buds, a bZIP transcription factor (TGA1a-like protein) was down-regulated, while up-regulated genes include auxin-regulated protein kinase, cyclophilin, and TCP-like genes. A retroelement clone was also preferentially expressed in the peloric mutant flowers. On the other hand, ESTs involved in DNA methylation, chromatin remodeling and post- transcriptional regulation, such as DNA methyltransferase, histone acetyltransferase, ERECTA, and DEAD/DEAH RNA helicase, were enriched in normal flower buds than the mutants. The enriched transcripts in the wild type indicate the down regulation of these transcripts in the mutants, and vice versa. The potential roles of the analyzed transcripts in the development of Phalaenopsis flowers are discussed.展开更多
Fusarium oxysporum f. sp. ciceri (Foc), one of the most important fungal pathogen of chickpea, is a constant threat to this crop plant. In the present study gene expression analysis of chickpea roots during Foc infect...Fusarium oxysporum f. sp. ciceri (Foc), one of the most important fungal pathogen of chickpea, is a constant threat to this crop plant. In the present study gene expression analysis of chickpea roots during Foc infection was performed using various approaches. cDNAs derived from total mRNA during infection process of susceptible (JG62)and resistant (Digvijay) cultivars, were amplified using random oligonucleotides. Sequence characterization of differentially expressed transcripts revealed their homology with many plant genes essential for various metabolic functions including defense. Further, expression patterns of specific candidate gene transcripts were analyzed in the Foc inoculated and uninoculated resistant and susceptible chickpea cultivars, on day 6 of infection. Semiquantitative RT-PCR analysis of defense related genes was performed using gene specific oligonucleotides in resistant and susceptible chickpea cultivars. The expression of fungal pathogenesis related genes and their race specific response was determined throughout the course of chickpea-Foc interaction. Temporal expression and race specific response of plant defense related and fungal virulence genes were studied in the resistant and susceptible cultivars of chickpea inoculated with three races of Foc highlighting the host-pathogen interactions. Few genes, involved in chickpea defense against Fusarium wilt which were not reported previously were unveiled in this study.展开更多
The differentially expressed cDNA fragments have been obtained by differential screening with cDNA-RAPD technique in photoperiod sensitive genic male sterile (PGMS) rice. Some of them have been reassessed with Norther...The differentially expressed cDNA fragments have been obtained by differential screening with cDNA-RAPD technique in photoperiod sensitive genic male sterile (PGMS) rice. Some of them have been reassessed with Northern blot hybridization, from which a PGMS-related positive fragment, RPG43, has been identified. Further analysis on RPG43 with Southern blot and RAPD indicates that the fragment is a single-copy sequence and its mRNA has been processed after transcription. Sequence analysis reveals that RPG43 is 744 bp in length and contains a 60 bp region (from 126th to 185th bp) showing 72% homology to a human DNA sequence, pac pDJ-356d6, on chromosome 11. So it is a new sequence found in plant and its GenBank access number is AF126027. In addition, RPG43 has been mapped to a position 3.8 cM away from RFLP marker R1553 on chromosome 5 of rice.展开更多
The fertile and sterile young panicle representational populations were constructed by bulked sampling method using young panicles in the photo-period sensitive stage of fertility transformation.Two populations were a...The fertile and sterile young panicle representational populations were constructed by bulked sampling method using young panicles in the photo-period sensitive stage of fertility transformation.Two populations were analyzed using cDNA-RAPD. The results showed that: ( ⅰ ) bulked sampling method can be employed to analyze differentially expressed genes using cDNA-RAPD, taking an advantage in avoiding false positive caused by conventional sampling method. (ⅱ) Among 150 random primers used, 83 primers amplified the same banding patterns, and 34 primers amplified the same banding pattern but different staining of intensity on gel. ( ⅲ ) 33 primers amplified differential cDNA bands between fertile and sterile cDNA populations, and the ratio of polymorphism was 22%. It is concluded that there may exist a lot of genes relating to sterility, which makes the differentially expressed cDNA fragments complicated.展开更多
文摘Tissue culture has been widely used for mass propagation of Phalaenopsis. However, somaclonal variation occurred during micropropagation process posed a severe problem by affecting product quality. In this study, wild type and peloric flower buds of Phalaenopsis hybrids derived from flower stalk nodal culture were used for cDNA-RAPD and cDNA suppression subtractive hybridization analyses in order to study their genetic difference in terms of expressed sequence tags. A total of 209 ESTs from normal flower buds and 230 from mutants were sequenced. These ESTs sequences can be grouped into several functional categories involved in different cellular processes including metabolism, signal transduction, transcription, cell growth and division, protein synthesis, and protein localization, and into a subcat- egory of proteins with unknown function. Cymbidium mosaic virus transcript was surprisingly found expressed fre- quently in the peloric mutant of P. Little Mary. Real-time RT-PCR analysis on selected ESTs showed that in mutant flower buds, a bZIP transcription factor (TGA1a-like protein) was down-regulated, while up-regulated genes include auxin-regulated protein kinase, cyclophilin, and TCP-like genes. A retroelement clone was also preferentially expressed in the peloric mutant flowers. On the other hand, ESTs involved in DNA methylation, chromatin remodeling and post- transcriptional regulation, such as DNA methyltransferase, histone acetyltransferase, ERECTA, and DEAD/DEAH RNA helicase, were enriched in normal flower buds than the mutants. The enriched transcripts in the wild type indicate the down regulation of these transcripts in the mutants, and vice versa. The potential roles of the analyzed transcripts in the development of Phalaenopsis flowers are discussed.
文摘Fusarium oxysporum f. sp. ciceri (Foc), one of the most important fungal pathogen of chickpea, is a constant threat to this crop plant. In the present study gene expression analysis of chickpea roots during Foc infection was performed using various approaches. cDNAs derived from total mRNA during infection process of susceptible (JG62)and resistant (Digvijay) cultivars, were amplified using random oligonucleotides. Sequence characterization of differentially expressed transcripts revealed their homology with many plant genes essential for various metabolic functions including defense. Further, expression patterns of specific candidate gene transcripts were analyzed in the Foc inoculated and uninoculated resistant and susceptible chickpea cultivars, on day 6 of infection. Semiquantitative RT-PCR analysis of defense related genes was performed using gene specific oligonucleotides in resistant and susceptible chickpea cultivars. The expression of fungal pathogenesis related genes and their race specific response was determined throughout the course of chickpea-Foc interaction. Temporal expression and race specific response of plant defense related and fungal virulence genes were studied in the resistant and susceptible cultivars of chickpea inoculated with three races of Foc highlighting the host-pathogen interactions. Few genes, involved in chickpea defense against Fusarium wilt which were not reported previously were unveiled in this study.
文摘The differentially expressed cDNA fragments have been obtained by differential screening with cDNA-RAPD technique in photoperiod sensitive genic male sterile (PGMS) rice. Some of them have been reassessed with Northern blot hybridization, from which a PGMS-related positive fragment, RPG43, has been identified. Further analysis on RPG43 with Southern blot and RAPD indicates that the fragment is a single-copy sequence and its mRNA has been processed after transcription. Sequence analysis reveals that RPG43 is 744 bp in length and contains a 60 bp region (from 126th to 185th bp) showing 72% homology to a human DNA sequence, pac pDJ-356d6, on chromosome 11. So it is a new sequence found in plant and its GenBank access number is AF126027. In addition, RPG43 has been mapped to a position 3.8 cM away from RFLP marker R1553 on chromosome 5 of rice.
文摘The fertile and sterile young panicle representational populations were constructed by bulked sampling method using young panicles in the photo-period sensitive stage of fertility transformation.Two populations were analyzed using cDNA-RAPD. The results showed that: ( ⅰ ) bulked sampling method can be employed to analyze differentially expressed genes using cDNA-RAPD, taking an advantage in avoiding false positive caused by conventional sampling method. (ⅱ) Among 150 random primers used, 83 primers amplified the same banding patterns, and 34 primers amplified the same banding pattern but different staining of intensity on gel. ( ⅲ ) 33 primers amplified differential cDNA bands between fertile and sterile cDNA populations, and the ratio of polymorphism was 22%. It is concluded that there may exist a lot of genes relating to sterility, which makes the differentially expressed cDNA fragments complicated.
