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资助项目
0.05). For some populations, germination capacity in 12-h photoperiod was significantly higher than that in completed darkness（W-FD: P < 0.01, W-JD: P < 0.05）.Genetic variation within and among six populations was assessed using AFLP markers. Genetic diversity was higher at species level (PPL = 69.19%, HE = 0.221) than at population level (PPL = 26.22%, HE = 0.095, Is =0.140), and populations in southeast Yunnan were strongly differentiated from those in southwest Yunnan (Nei’s GST = 0.575; FST = 0.655). UPGMA analysis demonstrated a clear genetic division between the two populations from DeHong (SW Yunnan; D-JD and D-HG) and the four from WenShan (SE Yunnan; W-FD, W-LH, W-ML, and W-MG). Within-population genetic variation was significantly correlated with population isolation (r(PPL) = -0.94, P = 0.006; r(HE) = -0.85, P = 0.032; r(Is) = -0.87, P = 0.025), but not with population size (r(PPL) = 0.63, P = 0.178; r(HE) = 0.54, P = 0.268; r(Is) = 0.56, P = 0.249).","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.type_filter&advanced=false&query1=MAINTENANCE&&fq=dc.project.title_filter%3ACraigia%5C+yunnanensis%5C+W.%5C+W.%5C+Smith%5C+%5C%26%5C+W.%5C+E.%5C+Evans%5C+%5C%28Tiliaceae%5C%29%5C+is%5C+an%5C+endangered%5C+deciduous%5C+tree%5C+species%5C+which%5C+has%5C+high%5C+scientific%5C+and%5C+economic%5C+value.%5C+C.%5C+yunnanensis%5C+is%5C+seriously%5C+threatened%5C+and%5C+has%5C+been%5C+pushed%5C+to%5C+the%5C+verge%5C+of%5C+extinction%5C+due%5C+to%5C+vegetation%5C+destruction%5C+in%5C+China%5C+and%5C+consequent%5C+contraction%5C+of%5C+its%5C+distribution.%5C+Hence%2C%5C+it%5C+was%5C+listed%5C+as%5C+a%5C+nationally%5C+rare%5C+and%5C+endangered%5C+plant%5C+in%5C+1999%5C+and%5C+has%5C+also%5C+been%5C+proposed%5C+as%5C+a%5C+second%5C-ranked%5C+plant%5C+for%5C+national%5C+protection%5C+in%5C+China%5C+and%5C+included%5C+in%5C+IUCN%5C+red%5C+list.%5C+As%5C+a%5C+scientifically%5C+important%5C+and%5C+valued%5C+tree%5C+species%5C+with%5C+endangered%5C+status%2C%5C+the%5C+wild%5C+populations%5C+of%5C+C.%5C+yunnanensis%5C+therefore%5C+represent%5C+is%5C+a%5C+genetic%5C+resource%5C+that%5C+must%5C+be%5C+conserved.%5C+To%5C+provide%5C+basic%5C+information%5C+for%5C+its%5C+conservation%2C%5C+the%5C+population%5C+dynamics%5C+and%5C+population%5C+size%5C+structures%2C%5C+pollination%5C+biology%5C+and%5C+breeding%5C+system%2C%5C+eleven%5C+fitness%5C-related%5C+characters%5C+and%5C+the%5C+genetic%5C+variability%5C+based%5C+on%5C+AFLP%5C+were%5C+comprehensively%5C+studied.%5C+The%5C+main%5C+results%5C+are%5C+summarized%5C+as%5C+follows%5C%3A%5C+A%5C+total%5C+of%5C+six%5C+wild%5C+populations%5C+of%5C+C.%5C+yunnanensis%5C+were%5C+found%5C+in%5C+two%5C+disjunct%5C+regions%5C+of%5C+Yunnan%2C%5C+i.e.%5C+WenShan%5C+%5C%28SE%5C+Yunnan%5C%29%5C+and%5C+DeHong%5C+%5C%28SW%5C+Yunnan%5C%29%2C%5C+from%5C+2005%5C+to%5C+2007.%5C+Additionally%2C%5C+in%5C+all%5C+but%5C+one%5C+of%5C+the%5C+populations%5C+we%5C+detected%2C%5C+mature%5C+trees%5C+were%5C+felled%5C+between%5C+2005%5C+and%5C+2007%2C%5C+so%5C+destruction%5C+of%5C+most%5C+of%5C+these%5C+populations%5C+is%5C+ongoing.%5C+Across%5C+the%5C+six%5C+populations%5C+of%5C+extant%5C+C.%5C+yunnanensis%5C+found%5C+during%5C+our%5C+study%2C%5C+the%5C+total%5C+number%5C+of%5C+mature%5C+%5C%28reproductive%5C%29%5C+individuals%5C+detected%5C+was%5C+584%5C+in%5C+2007%EF%BC%8Cplus%5C+larger%5C+numbers%5C+of%5C+seedling%5C+and%5C+resprouts%5C+from%5C+cut%5C+trunks.%5C+The%5C+result%5C+of%5C+surveying%5C+Population%5C+structure%5C+showed%5C+that%5C+there%5C+are%5C+two%5C+regeneration%5C+types%5C+which%5C+are%5C+seedlings%5C+and%5C+sprouts.%5C+Seedlings%5C+occurred%5C+abundantly%5C+in%5C+gaps%5C+or%5C+open%5C+areas%5C+and%5C+the%5C+size%5C+class%5C+frequency%5C+distributions%5C+were%5C+often%5C+discontinuous%2C%5C+and%5C+the%5C+same%5C+general%5C+pattern%5C+occurred%5C+in%5C+all%5C+the%5C+investigated%5C+populations%5C+for%5C+juveniles%5C+and%5C+adults.%5C+The%5C+numbers%5C+of%5C+seed%5C-origin%5C+individuals%5C+did%5C+however%5C+decline%5C+sharply%5C+with%5C+increasing%5C+size%2C%5C+indicating%5C+a%5C+high%5C+mortality%5C+rate%5C+going%5C+from%5C+seedling%5C+to%5C+sapling%5C+stage%5C+may%5C+be%5C+a%5C+problem%5C+for%5C+this%5C+species.%5C+Additionally%2C%5C+the%5C+cash%5C+crop%5C+cultivation%5C+and%5C+logging%5C+seriously%5C+threaten%5C+the%5C+survival%5C+of%5C+the%5C+species.%5C+We%5C+conducted%5C+field%5C+observations%5C+and%5C+artificial%5C+pollination%5C+experiments%5C+on%5C+the%5C+floral%5C+biology%2C%5C+pollination%5C+process%5C+and%5C+breeding%5C+system%5C+of%5C+Craigia%5C+yunnanensis%5C+in%5C+Fadou%2C%5C+Xichou%5C+county%5C+of%5C+Yunnan%5C+province.%5C+The%5C+lifespan%5C+of%5C+a%5C+single%5C+hermaphrodite%5C+flower%5C+is%5C+approximately%5C+3%5C-4%5C+days.%5C+A%5C+cyme%5C+has%5C+2%5C-9%5C+flowered.%5C+The%5C+flowering%5C+period%5C+of%5C+an%5C+inflorescence%5C+is%5C+usually%5C+5%5C-14%5C+days.%5C+The%5C+flowers%5C+of%5C+C.%5C+yunnanensis%5C+were%5C+protandrous.%5C+The%5C+stamens%5C+were%5C+within%5C+petal%5C-like%5C+staminodes%5C+in%5C+the%5C+opening%5C+flowers%5C+until%5C+the%5C+flower%5C+withered.%5C+Without%5C+touchment%2C%5C+the%5C+bractlike%5C+staminodes%5C+can%E2%80%99t%5C+open.%5C+Self%5C-pollination%5C+was%5C+partially%5C+avoided%5C+by%5C+temporal%5C+and%5C+spatial%5C+isolation%5C+of%5C+male%5C+and%5C+female%5C+organs%5C+within%5C+the%5C+same%5C+flower.%5C+However%2C%5C+autogamous%5C+and%5C+geitonogamous%5C+pollination%5C+is%5C+unavoidable%5C+because%5C+of%5C+the%5C+large%5C+number%5C+of%5C+flowers%5C+on%5C+a%5C+single%5C+tree%5C+and%5C+the%5C+action%5C+of%5C+pollinators.%5C+The%5C+values%5C+of%5C+both%5C+OCI%5C+%5C%28%E2%89%A54%5C%29%5C+and%5C+P%5C%2FO%5C+%5C%281381%5C%29%5C+and%5C+the%5C+results%5C+of%5C+bagging%5C+tests%5C+indicated%5C+there%5C+was%5C+no%5C+apomixes%5C+in%5C+C.%5C+yunnanensis%5C+and%5C+the%5C+breeding%5C+system%5C+of%5C+the%5C+species%5C+was%5C+outcrossing%5C+with%5C+partial%5C+self%5C-compatibility%5C+and%5C+the%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Science Foundation[15-23242S]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.type_filter&advanced=false&query1=MAINTENANCE&&fq=dc.project.title_filter%3ACzech%5C+Science%5C+Foundation%5C%5B15%5C-23242S%5C%5D"},{"jsname":"Czech Science Foundation[16-26369S]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.type_filter&advanced=false&query1=MAINTENANCE&&fq=dc.project.title_filter%3ACzech%5C+Science%5C+Foundation%5C%5B16%5C-26369S%5C%5D"},{"jsname":"Environmental stresses could limit plant growth, development and propagation. Abiotic stress refers to the negative impact factors to the plants, such as extreme temperature, drought, flood, salinity, irradiation, chemicals and so on. To understand the mechanism of abiotic stress is very important.Membrane is the most sensitive organs in the cell that response to environmental changes. Cells respond and transduct environmental signals by changing content of membrane lipids and membrane proteins. The activity change of membrane phospholipase D (PLD) and the composition and content of membrane lipid molecules is one of the most anti-stress methods for the plants. It was reported that plants responded to some abiotic stresses such as freezing, thawing, seed aging and dehydration through changing lipid molecules especially the messenger phosphatidic acid (PA) and mutants of PLD were more tolerant to those stresses. It is important to investigate the characteristics and variation of membrane lipids and membrane proteins to understand the streee in plants.Three different kinds of stresses, including alpine scree temperature stress, allelopathy and Gamma irradiation stress, were studied in the present dissertation. And try to understand how plants response to those stresses by changing membrane system and the function of PLD in resistant to those stresses, lipidomic methods were used to profiling the changing of 11 lipids classes (160 lipids molecules) under thoses stresses. Moreover, PLD mutants were also used to study the role of PLD under those stresses. The mechanisms of plants response to stresses were very complicated; PLD and lipid molecules were not the only factors that response to stresses, the metabolism and phytohormones of tested plants under these stresses were also studied.In alpine scree of northwest Yunnan, the temperature was various from 33 °C during the midday to 4 °C at night, and the highest temperature could reach to 35 to 40 °C. Saussurea medusa and Solms-Laubachia linearifolia, which live in this environment, were chosen as studied model. The results showed that membrane lipid of these two plants significantly fluctuated with the temperature, while the double bond index (DBI) that had close relationship to temperature did not change. Furthermore, the the lysolipids which rise significantly under stresses did not change too much either. Laboratory mimic experiments also confermed the characteristics of lipids change to temperature in alpine scree plants. The results suggested that the plants living in such temperature changeable environment had already adapted to this situation and their membrane responded to the temperature was a kind of adaptation instead of stress response.Since the first introduction in Yunnan province of China in 1940s, E. adenophorum has spread very rapidly especially in southwestern China. Without understanding its invasive mechanism, it is impossible to control it. o-Hydroxycinnamic acid (o-HCA), an allelochmeical isolated from leachates of aerial parts of E. adenophorum were studied. o-HCA was abundant in aerial parts of E. adenophorum (1g/10kg fresh weight). The data showed that o-HCA not only had strong allelopathic effect on Arabidopsis seeds germination, but also inhibited seedling growth, and even induced root death of Arabidopsis seedlings. It could be proposed that o-HCA affected seedlings indirectly, through inducing root cell death, and it disturbed the water and ion absorption of plants and finally induced seedling to die. Interestingly, o-HCA could also inhibit E. adenophorum seed germination, while it showed no effect on its seedling growth. E. adenophorum can produce thousands of seeds and has the ability to vegetative reproduction, with which may alleviate the harmful effect of o-HCA on E. adenophorum. Unlike E. adenophorum, its neighbors’ population was inhibited, under this situation, E. adenophorum coule have better condition to live and invade successfully.Arabidopsis were irradiated with gamma rays, and 50-100 Gy gamma irradiation could inhibit seedling growth, and with the dosage above 200 Gy it could inhibit seedling flowering. Treated Arabidopsis wild types and their PLD a and d mutant with gamma ray showed no significant differences among them. The lipid molecules changes of seedlings under stress of gamma ray were also tested, and found that Gamama ray induced lipids degradation, among which, MGDG and DGDG degraded dramatically, while the average carbons in lipids did not changed. The lipids content (nmol per mg dry weight) decreased significantly, while the mol% content (mol% of total) changed slightly. Gamma irradiation also leaded to dramatically change of Arabidopsis seedling metabolomics and the phytohormones (ABA，ZR，JA，IAA).","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.type_filter&advanced=false&query1=MAINTENANCE&&fq=dc.project.title_filter%3AEnvironmental%5C+stresses%5C+could%5C+limit%5C+plant%5C+growth%2C%5C+development%5C+and%5C+propagation.%5C+Abiotic%5C+stress%5C+refers%5C+to%5C+the%5C+negative%5C+impact%5C+factors%5C+to%5C+the%5C+plants%2C%5C+such%5C+as%5C+extreme%5C+temperature%2C%5C+drought%2C%5C+flood%2C%5C+salinity%2C%5C+irradiation%2C%5C+chemicals%5C+and%5C+so%5C+on.%5C+To%5C+understand%5C+the%5C+mechanism%5C+of%5C+abiotic%5C+stress%5C+is%5C+very%5C+important.Membrane%5C+is%5C+the%5C+most%5C+sensitive%5C+organs%5C+in%5C+the%5C+cell%5C+that%5C+response%5C+to%5C+environmental%5C+changes.%5C+Cells%5C+respond%5C+and%5C+transduct%5C+environmental%5C+signals%5C+by%5C+changing%5C+content%5C+of%5C+membrane%5C+lipids%5C+and%5C+membrane%5C+proteins.%5C+The%5C+activity%5C+change%5C+of%5C+membrane%5C+phospholipase%5C+D%5C+%5C%28PLD%5C%29%5C+and%5C+the%5C+composition%5C+and%5C+content%5C+of%5C+membrane%5C+lipid%5C+molecules%5C+is%5C+one%5C+of%5C+the%5C+most%5C+anti%5C-stress%5C+methods%5C+for%5C+the%5C+plants.%5C+It%5C+was%5C+reported%5C+that%5C+plants%5C+responded%5C+to%5C+some%5C+abiotic%5C+stresses%5C+such%5C+as%5C+freezing%2C%5C+thawing%2C%5C+seed%5C+aging%5C+and%5C+dehydration%5C+through%5C+changing%5C+lipid%5C+molecules%5C+especially%5C+the%5C+messenger%5C+phosphatidic%5C+acid%5C+%5C%28PA%5C%29%5C+and%5C+mutants%5C+of%5C+PLD%5C+were%5C+more%5C+tolerant%5C+to%5C+those%5C+stresses.%5C+It%5C+is%5C+important%5C+to%5C+investigate%5C+the%5C+characteristics%5C+and%5C+variation%5C+of%5C+membrane%5C+lipids%5C+and%5C+membrane%5C+proteins%5C+to%5C+understand%5C+the%5C+streee%5C+in%5C+plants.Three%5C+different%5C+kinds%5C+of%5C+stresses%2C%5C+including%5C+alpine%5C+scree%5C+temperature%5C+stress%2C%5C+allelopathy%5C+and%5C+Gamma%5C+irradiation%5C+stress%2C%5C+were%5C+studied%5C+in%5C+the%5C+present%5C+dissertation.%5C+And%5C+try%5C+to%5C+understand%5C+how%5C+plants%5C+response%5C+to%5C+those%5C+stresses%5C+by%5C+changing%5C+membrane%5C+system%5C+and%5C+the%5C+function%5C+of%5C+PLD%5C+in%5C+resistant%5C+to%5C+those%5C+stresses%2C%5C+lipidomic%5C+methods%5C+were%5C+used%5C+to%5C+profiling%5C+the%5C+changing%5C+of%5C+11%5C+lipids%5C+classes%5C+%5C%28160%5C+lipids%5C+molecules%5C%29%5C+under%5C+thoses%5C+stresses.%5C+Moreover%2C%5C+PLD%5C+mutants%5C+were%5C+also%5C+used%5C+to%5C+study%5C+the%5C+role%5C+of%5C+PLD%5C+under%5C+those%5C+stresses.%5C+The%5C+mechanisms%5C+of%5C+plants%5C+response%5C+to%5C+stresses%5C+were%5C+very%5C+complicated%5C%3B%5C+PLD%5C+and%5C+lipid%5C+molecules%5C+were%5C+not%5C+the%5C+only%5C+factors%5C+that%5C+response%5C+to%5C+stresses%2C%5C+the%5C+metabolism%5C+and%5C+phytohormones%5C+of%5C+tested%5C+plants%5C+under%5C+these%5C+stresses%5C+were%5C+also%5C+studied.In%5C+alpine%5C+scree%5C+of%5C+northwest%5C+Yunnan%2C%5C+the%5C+temperature%5C+was%5C+various%5C+from%5C+33%5C+%C2%B0C%5C+during%5C+the%5C+midday%5C+to%5C+4%5C+%C2%B0C%5C+at%5C+night%2C%5C+and%5C+the%5C+highest%5C+temperature%5C+could%5C+reach%5C+to%5C+35%5C+to%5C+40%5C+%C2%B0C.%5C+Saussurea%5C+medusa%5C+and%5C+Solms%5C-Laubachia%5C+linearifolia%2C%5C+which%5C+live%5C+in%5C+this%5C+environment%2C%5C+were%5C+chosen%5C+as%5C+studied%5C+model.%5C+The%5C+results%5C+showed%5C+that%5C+membrane%5C+lipid%5C+of%5C+these%5C+two%5C+plants%5C+significantly%5C+fluctuated%5C+with%5C+the%5C+temperature%2C%5C+while%5C+the%5C+double%5C+bond%5C+index%5C+%5C%28DBI%5C%29%5C+that%5C+had%5C+close%5C+relationship%5C+to%5C+temperature%5C+did%5C+not%5C+change.%5C+Furthermore%2C%5C+the%5C+the%5C+lysolipids%5C+which%5C+rise%5C+significantly%5C+under%5C+stresses%5C+did%5C+not%5C+change%5C+too%5C+much%5C+either.%5C+Laboratory%5C+mimic%5C+experiments%5C+also%5C+confermed%5C+the%5C+characteristics%5C+of%5C+lipids%5C+change%5C+to%5C+temperature%5C+in%5C+alpine%5C+scree%5C+plants.%5C+The%5C+results%5C+suggested%5C+that%5C+the%5C+plants%5C+living%5C+in%5C+such%5C+temperature%5C+changeable%5C+environment%5C+had%5C+already%5C+adapted%5C+to%5C+this%5C+situation%5C+and%5C+their%5C+membrane%5C+responded%5C+to%5C+the%5C+temperature%5C+was%5C+a%5C+kind%5C+of%5C+adaptation%5C+instead%5C+of%5C+stress%5C+response.Since%5C+the%5C+first%5C+introduction%5C+in%5C+Yunnan%5C+province%5C+of%5C+China%5C+in%5C+1940s%2C%5C+E.%5C+adenophorum%5C+has%5C+spread%5C+very%5C+rapidly%5C+especially%5C+in%5C+southwestern%5C+China.%5C+Without%5C+understanding%5C+its%5C+invasive%5C+mechanism%2C%5C+it%5C+is%5C+impossible%5C+to%5C+control%5C+it.%5C+o%5C-Hydroxycinnamic%5C+acid%5C+%5C%28o%5C-HCA%5C%29%2C%5C+an%5C+allelochmeical%5C+isolated%5C+from%5C+leachates%5C+of%5C+aerial%5C+parts%5C+of%5C+E.%5C+adenophorum%5C+were%5C+studied.%5C+o%5C-HCA%5C+was%5C+abundant%5C+in%5C+aerial%5C+parts%5C+of%5C+E.%5C+adenophorum%5C+%5C%281g%5C%2F10kg%5C+fresh%5C+weight%5C%29.%5C+The%5C+data%5C+showed%5C+that%5C+o%5C-HCA%5C+not%5C+only%5C+had%5C+strong%5C+allelopathic%5C+effect%5C+on%5C+Arabidopsis%5C+seeds%5C+g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Research Funds for the Central Universities[17l-gzd24]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.type_filter&advanced=false&query1=MAINTENANCE&&fq=dc.project.title_filter%3AFundamental%5C+Research%5C+Funds%5C+for%5C+the%5C+Central%5C+Universities%5C%5B17l%5C-gzd24%5C%5D"},{"jsname":"How has natural selection determined the evolution of gene regulation by acting on major regulatory factors? This question has been attractive to many evolutionary biologists for a long time. MicroRNAs (miRNAs) are endogenous posttranscriptional repressors and play essential roles in diverse biological processes in plants. To understand how natural selection has targeted on the entire lay of miRNA regulatory modules during flower development, we resequenced 31 miRNA target sites involved in flower development from five rice populations. We found that purifying selection serves as a major evolutionary force to act on the conserved miRNA binding sites, leading to the globally reduced genetic variation in highly conserved miRNA binding sequences within the entire rice samples. Conversely, positive selection allows variations at nonconserved miRNA binding sites and acts on them in a population-specific behaviour. Further analysis revealed that the polymorphisms within target sites may serve as raw materials for diverse functions of miRNAs by means of the destabilization of duplex, abolishment of existing target sites, and creation of novel ones. Together, the above-mentioned results indicate that variations at conserved binding sites are likely deleterious during rice flower development, whereas variants at nonconserved binding sites may be conductive to flower development-related phenotypic diversities and rice population adaption to variable environmental conditions as well. To further assess functional effects and evolutionary significance of variable alleles at the target genes, we reported the detailed characterization of the haplotype and linkage disequilibrium (LD) patterns of the entire target gene (LOC_Os01g18850，SPL 1) and the 1.4 Mb flanking regions in three rice populations, namely japonica, indica and O. rufipogon. The genetic profile of SNPs at target site and its flanking regions revealed high haplotype frequency, low haplotype diversity and strong LD in two cultivatedricepopulations. By contrast, we observed the opposite phenomena in O. rufipogon. Using the long-range haplotype (LRT) test, we found strong evidence of recent positive selection for SNP 3C/T alleles at target site in the combined O. sativa. Comparsion between the two rice subpopulations indicated that the major haplotype mh 2 containing SNP 3C accounts for half of all haplotypes in indica, while mh 3 containing SNP 3T is 91% in japonica. Moreover, the extent of LD is stronger in japonica than that in inidca. These differences suggest that independent evolutionary events may have occurred in target sequences of two cultivated rice populations and stronger positive selection acted on japonica. Next, we examined geographic distribution of polymorphic variants at target sites. We found that the major alleles SNP 3T and tightly linked SNP 4A in japonica appear to be associated with the adaption to the northern climates during rice flower development.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.type_filter&advanced=false&query1=MAINTENANCE&&fq=dc.project.title_filter%3AHow%5C+has%5C+natural%5C+selection%5C+determined%5C+the%5C+evolution%5C+of%5C+gene%5C+regulation%5C+by%5C+acting%5C+on%5C+major%5C+regulatory%5C+factors%5C%3F%5C+This%5C+question%5C+has%5C+been%5C+attractive%5C+to%5C+many%5C+evolutionary%5C+biologists%5C+for%5C+a%5C+long%5C+time.%5C+MicroRNAs%5C+%5C%28miRNAs%5C%29%5C+are%5C+endogenous%5C+posttranscriptional%5C+repressors%5C+and%5C+play%5C+essential%5C+roles%5C+in%5C+diverse%5C+biological%5C+processes%5C+in%5C+plants.%5C+To%5C+understand%5C+how%5C+natural%5C+selection%5C+has%5C+targeted%5C+on%5C+the%5C+entire%5C+lay%5C+of%5C+miRNA%5C+regulatory%5C+modules%5C+during%5C+flower%5C+development%2C%5C+we%5C+resequenced%5C+31%5C+miRNA%5C+target%5C+sites%5C+involved%5C+in%5C+flower%5C+development%5C+from%5C+five%5C+rice%5C+populations.%5C+We%5C+found%5C+that%5C+purifying%5C+selection%5C+serves%5C+as%5C+a%5C+major%5C+evolutionary%5C+force%5C+to%5C+act%5C+on%5C+the%5C+conserved%5C+miRNA%5C+binding%5C+sites%2C%5C+leading%5C+to%5C+the%5C+globally%5C+reduced%5C+genetic%5C+variation%5C+in%5C+highly%5C+conserved%5C+miRNA%5C+binding%5C+sequences%5C+within%5C+the%5C+entire%5C+rice%5C+samples.%5C+Conversely%2C%5C+positive%5C+selection%5C+allows%5C+variations%5C+at%5C+nonconserved%5C+miRNA%5C+binding%5C+sites%5C+and%5C+acts%5C+on%5C+them%5C+in%5C+a%5C+population%5C-specific%5C+behaviour.%5C+Further%5C+analysis%5C+revealed%5C+that%5C+the%5C+polymorphisms%5C+within%5C+target%5C+sites%5C+may%5C+serve%5C+as%5C+raw%5C+materials%5C+for%5C+diverse%5C+functions%5C+of%5C+miRNAs%5C+by%5C+means%5C+of%5C+the%5C+destabilization%5C+of%5C+duplex%2C%5C+abolishment%5C+of%5C+existing%5C+target%5C+sites%2C%5C+and%5C+creation%5C+of%5C+novel%5C+ones.%5C+Together%2C%5C+the%5C+above%5C-mentioned%5C+results%5C+indicate%5C+that%5C+variations%5C+at%5C+conserved%5C+binding%5C+sites%5C+are%5C+likely%5C+deleterious%5C+during%5C+rice%5C+flower%5C+development%2C%5C+whereas%5C+variants%5C+at%5C+nonconserved%5C+binding%5C+sites%5C+may%5C+be%5C+conductive%5C+to%5C+flower%5C+development%5C-related%5C+phenotypic%5C+diversities%5C+and%5C+rice%5C+population%5C+adaption%5C+to%5C+variable%5C+environmental%5C+conditions%5C+as%5C+well.%5C+To%5C+further%5C+assess%5C+functional%5C+effects%5C+and%5C+evolutionary%5C+significance%5C+of%5C+variable%5C+alleles%5C+at%5C+the%5C+target%5C+genes%2C%5C+we%5C+reported%5C+the%5C+detailed%5C+characterization%5C+of%5C+the%5C+haplotype%5C+and%5C+linkage%5C+disequilibrium%5C+%5C%28LD%5C%29%5C+patterns%5C+of%5C+the%5C+entire%5C+target%5C+gene%5C+%5C%28LOC_Os01g18850%EF%BC%8CSPL%5C+1%5C%29%5C+and%5C+the%5C+1.4%5C+Mb%5C+flanking%5C+regions%5C+in%5C+three%5C+rice%5C+populations%2C%5C+namely%5C+japonica%2C%5C+indica%5C+and%5C+O.%5C+rufipogon.%5C+The%5C+genetic%5C+profile%5C+of%5C+SNPs%5C+at%5C+target%5C+site%5C+and%5C+its%5C+flanking%5C+regions%5C+revealed%5C+high%5C+haplotype%5C+frequency%2C%5C+low%5C+haplotype%5C+diversity%5C+and%5C+strong%5C+LD%5C+in%5C+two%5C+cultivatedricepopulations.%5C+By%5C+contrast%2C%5C+we%5C+observed%5C+the%5C+opposite%5C+phenomena%5C+in%5C+O.%5C+rufipogon.%5C+Using%5C+the%5C+long%5C-range%5C+haplotype%5C+%5C%28LRT%5C%29%5C+test%2C%5C+we%5C+found%5C+strong%5C+evidence%5C+of%5C+recent%5C+positive%5C+selection%5C+for%5C+SNP%5C+3C%5C%2FT%5C+alleles%5C+at%5C+target%5C+site%5C+in%5C+the%5C+combined%5C+O.%5C+sativa.%5C+Comparsion%5C+between%5C+the%5C+two%5C+rice%5C+subpopulations%5C+indicated%5C+that%5C+the%5C+major%5C+haplotype%5C+mh%5C+2%5C+containing%5C+SNP%5C+3C%5C+accounts%5C+for%5C+half%5C+of%5C+all%5C+haplotypes%5C+in%5C+indica%2C%5C+while%5C+mh%5C+3%5C+containing%5C+SNP%5C+3T%5C+is%5C+91%25%5C+in%5C+japonica.%5C+Moreover%2C%5C+the%5C+extent%5C+of%5C+LD%5C+is%5C+stronger%5C+in%5C+japonica%5C+than%5C+that%5C+in%5C+inidca.%5C+These%5C+differences%5C+suggest%5C+that%5C+independent%5C+evolutionary%5C+events%5C+may%5C+have%5C+occurred%5C+in%5C+target%5C+sequences%5C+of%5C+two%5C+cultivated%5C+rice%5C+populations%5C+and%5C+stronger%5C+positive%5C+selection%5C+acted%5C+on%5C+japonica.%5C+Next%2C%5C+we%5C+examined%5C+geographic%5C+distribution%5C+of%5C+polymorphic%5C+variants%5C+at%5C+target%5C+sites.%5C+We%5C+found%5C+that%5C+the%5C+major%5C+alleles%5C+SNP%5C+3T%5C+and%5C+tightly%5C+linked%5C+SNP%5C+4A%5C+in%5C+japonica%5C+appear%5C+to%5C+be%5C+associated%5C+with%5C+the%5C+adaption%5C+to%5C+the%5C+northern%5C+climates%5C+during%5C+rice%5C+flower%5C+development."},{"jsname":"Major Program of NSFC[31590823]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.type_filter&advanced=false&query1=MAINTENANCE&&fq=dc.project.title_filter%3AMajor%5C+Program%5C+of%5C+NSFC%5C%5B31590823%5C%5D"},{"jsname":"lastIndexed","jscount":"2024-06-22"}],"资助项目","dc.project.title_filter")'>
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