Short Retraction Notice The paper does not meet the standards of "Advances in Bioscience and Biotechnology". This article has been retracted to straighten the academic record. In making this decision the Edi...Short Retraction Notice The paper does not meet the standards of "Advances in Bioscience and Biotechnology". This article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's Retraction Guidelines. The aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused. Editor guiding this retraction: Prof. Abass Alavi (EiC of ABB). Please see the article page for more details. The full retraction notice in PDF is preceding the original paper which is marked "RETRACTED".展开更多
Interpretation of primary growth markers (modules) is neglected in sustainable resource management processes, yet it opens up prospects for long time series on tree crown development, necessary for their characterizat...Interpretation of primary growth markers (modules) is neglected in sustainable resource management processes, yet it opens up prospects for long time series on tree crown development, necessary for their characterization in the current context of climate change. This study aimed to assess the morphological variation of crown shoots in <i><span style="font-family:Verdana;">Parkia biglobosa</span></i><span style="font-family:Verdana;"> in the face of a changing environment. Axis growth modules of 420 individuals of different ages were retrospectively analyzed in the presence or absence of shading during the wet and dry seasons in seven localities in Cote d’Ivoire. The results showed that the developmental environment of individuals did not influence the growth modules dimensions (P > 0.05). However, module size remained significantly different between locations (P < 0.05). The southern part of the gradient is still favourable and has priority for the establishment of permanent plots. The modules morphology differs from the youngest to the oldest individuals (P < 0.05). The rainy season remains the ideal period for the implementation of agroforestry reforestation programmes based on this species (P < 0.05). </span><i><span style="font-family:Verdana;">Parkia biglobosa</span></i><span style="font-family:Verdana;"> is a monochasial sympod (Pseudo-monopod) with a relay axis that follows the Paul Champagnat architectural model in the young stage, and transits to the Wilhelm Troll model later in the adult and old stage. This information contributes to the understanding of the functioning of crown and the adaptation of this species to a varying environment. It could guide choice of suitable environment and ideal genotype for the implementation of a reforestation or agroforestry programme based on </span><i><span style="font-family:Verdana;">Parkia biglobosa</span></i><span style="font-family:Verdana;">.</span>展开更多
In this work we compared the effect of the growth regulator content of the culture medium on the growth of in vitro shoot tips of five yam accessions belonging to four yam species (one Dioscorea alata, one D. rotundat...In this work we compared the effect of the growth regulator content of the culture medium on the growth of in vitro shoot tips of five yam accessions belonging to four yam species (one Dioscorea alata, one D. rotundata, one D. cayenensis and two D. trifida). Medium S contained 0.6 μM benzyl adenine, 1.07 μM naphthalene acetic acid and 0.23 μM gibberellic acid while medium EBR contained 0.23 μM gibberellic acid and 0.1 μM 24-epibrassinolide. After 2 months of culture, oxidation level was significantly reduced on medium EBR compared to medium S for four of the five accessions tested. By contrast, medium EBR did not have any positive effect on shoot length since length of shoots produced after 2 months of culture on medium S and EBR were similar, except with accession 3-45T, for which shoot length was shorter on medium S compared to medium EBR. These results underline the potential of 24-epibrassinolide to reduce oxidation phenomena during in vitro culture and call for its utilization for regeneration of cryopreserved yam shoot tips, which is often impeded by oxidation phenomena.展开更多
The rapid rate of deforestation in Cote d’Ivoire has led to loss of plant species diversity and also threatens some commercial tree species with extinction.Some reforestation and aff orestation has been completed.How...The rapid rate of deforestation in Cote d’Ivoire has led to loss of plant species diversity and also threatens some commercial tree species with extinction.Some reforestation and aff orestation has been completed.However,for some species,the numbers of surviving transplants has declined.Hence,it is necessary to develop properly adapted and resilient genotypes that can eff ectively support the programs of forest restoration.In this context we evaluated the eff ects of the provenances of seeds and of various treatments on the germination rates and on plant growth of four commercial trees species(Pycnanthus angolensis,Terminalia superba,Mansonia altissima and Pterygota macrocarpa).We analyzed these parameters for seeds of three provenances(Daloa,Akoupéand Daoukro)of four species and for thirty plants aged 6 months per provenance.Time to begin germination and time to reach maximum germination were similar among species,and were not infl uenced by either treatment or provenance.Untreated seeds and those soaked for 24 and 48 h in water at room temperature yielded the highest germination rates,irrespective of species or provenance.The one exception was P.angolensis,for which no germination was recorded.Within species,some provenances produced higher germination percentages than did others.No clear relationship was computed between the germination rate and the morphometric characteristics of the seeds which varied signifi cantly between provenances.Plant growth and morphological variability also depended greatly on provenance.Genetic factors might be implicated,therefore provenance trials should be undertaken and evaluated.Furthermore,molecular analysis should be undertaken to confi rm the implications of genetic factors and allow for genetic selection.展开更多
Uncaria tomentosa presents tomentum that resembles cat’s claws, hence its common name, is a plant that produces various secondary metabolites that are traditionally used in alternative medicine. The natural distribut...Uncaria tomentosa presents tomentum that resembles cat’s claws, hence its common name, is a plant that produces various secondary metabolites that are traditionally used in alternative medicine. The natural distribution of this species has been affected by indiscriminate harvesting from its habitat. In the present research, cryopreservation (liquid nitrogen, LN, -196°C) was evaluated as an option for ex situ conservation of this species. The following techniques were evaluated: vitrification and encapsulation-dehydration of apices, vitrification of cell suspensions, and seed desiccation and vitrification. Preculture conditions and exposure times to LS and PVS2 were evaluated. Apex survival was the highest (82%) with preculture in 0.25 M sucrose followed by incubation for 20 and 30 min in LS and PVS2, respectively, prior to cooling in LN. The encapsulation-dehydration technique was evaluated by using sucrose preculture and different capsule moisture contents. Survival of apices cooled in LN was not significantly different between treatments and varied from 31.8% to 52.9% for capsule moisture contents between 22.7% and 20.3%. For cell suspensions precultured in 0.5 M sucrose, cell multiplication and formation of calli with very good appearance were observed in 61.1% of the cultures following vitrification. For cryopreservation of seeds, germination was 89.5% using the desiccation technique and 67.6% to78.1% using vitrification.展开更多
Jatropha curcas is a species with a variety of uses. It is grown primarily for oil for biodiesel, but also has agronomic and medicinal applications. Two methods were evaluated for cryopreservation of seeds and zygotic...Jatropha curcas is a species with a variety of uses. It is grown primarily for oil for biodiesel, but also has agronomic and medicinal applications. Two methods were evaluated for cryopreservation of seeds and zygotic embryos of J. curcas: desiccation followed by rapid immersion of seeds and embryos in liquid nitrogen (LN, -196°C), and vitrification of zygotic embryos. Prior to cryo-preservation, seeds were manually scarified and the moisture content (MC) of seeds and embryos was determined. Explants were disinfected after cryopreservation. Seed germination after LN exposure was 100%. Plantlet development was better in sand substrate than that in vitro. Survival of zygotic embryos after cryopreservation was also 100%, without significant differences between treatments. Optimal development (100%) and plantlet length (51.77 mm) were observed with embryos dried for 60 min to 9.4% MC under laminar flow prior to cryopreservation. Zygotic embryos subjected to the vitrification procedure did not withstand LN exposure. Survival data for non-cryopreserved embryos after each step of the vitrification procedure provided information about embryo tolerance to cryoprotectants.展开更多
Many publications describe cryopreservation techniques but only a few studies have focused on the biochemical and physiological changes occurring in plants regenerated from seeds exposed to liquid nitrogen. This paper...Many publications describe cryopreservation techniques but only a few studies have focused on the biochemical and physiological changes occurring in plants regenerated from seeds exposed to liquid nitrogen. This paper aims at describing the effect of common bean seed cryostorage on mineral nutrition of young plantlets. The following elements were measured on leaves of 10-day-old plantlets from non-cryopreserved and cryopreserved seeds: Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, S, Se, Sr and Zn. At 10 days after sowing, both treatments (control and cryopreserved seeds) showed 100% seed germination without any visual phenotypic difference. However, contents of several elements in the leaves were different. Exposure of seeds to liquid nitrogen decreased Cu, Cd and Na uptake and increased absorption of B and Al. Further studies are required to understand the mechanisms underlying the relationship between seed exposure to liquid nitrogen and mineral nutrition during the early stages of plantlet growth.展开更多
The date palm (Phoenix dactylifera L.), a dioecious species, is of particular interest in the Sahel due to its phenological plasticity in relation to climate change and its double-flowering capacity. This article expl...The date palm (Phoenix dactylifera L.), a dioecious species, is of particular interest in the Sahel due to its phenological plasticity in relation to climate change and its double-flowering capacity. This article explores local practices and knowledge associated with date palm cultivation in the oasis basins of southeastern Niger, and provides an inventory of local seed propagated varieties, for more effectively guiding agricultural research and the breeding of this species. We carried out a survey of 30 date palm growers in 14 villages of the Manga region. The qualitative data of the survey were processed by a Multiple Correspondence Analysis. We inventoried 19 date palm varieties, for which the main distinctive criterion was fruit colour, but some other criteria such as biology or provenance were also used. The cultural practices and knowledge associated with the date palm in Manga have improved since the 1990s. They also depend on ethnic groups and the importance they assign to farming compared to livestock rearing and trading activities. The type of basin (high, intermediate, or low water table) influences growers’ practices and perceptions. Lastly, the date harvest in the wet season is abundant, but of mediocre quality, whereas it is the opposite for the dry season harvest. To conclude, sustainable development of date palm cultivation in the Sahel zone relies firstly on the selection of varieties that are early fruit producers or that can complete fruit maturation during the raining season and secondly on technical capacity building for producers.展开更多
Proline has been shown to accumulate in plants in response to biotic and abiotic stresses. Exogenous proline has thus been used for improving some plant cryopreservation protocols. Further enhancement of cryopreservat...Proline has been shown to accumulate in plants in response to biotic and abiotic stresses. Exogenous proline has thus been used for improving some plant cryopreservation protocols. Further enhancement of cryopreservation efficiency for in vitro grapevines could be expected if stresses linked to cryopreservation procedures could be reduced. We therefore studied the possible beneficial effect of proline in grapevine cryopreservation. Single-node explants from in vitro grown grapevine plantlets (Vitis vinifera L. cv Portan) were cultured on shooting media (half-strength MS + 1 μM BAP) containing no proline (control) or 50, 500, or 2000 μM filter-sterilized L-proline. Shoot tips excised from these microshoots were subjected to a PVS2-based droplet-vitrification procedure. Control and rewarmed explants were grown on a recovery medium containing 1 μM BAP. Shoot development on control medium and lower proline concentrations did not notably differ whereas the highest concentration of proline inhibited shoot development. Carry-over effects were observed since lower survival and regrowth were obtained both for non-frozen or LN-treated explants excised from micro-shoots obtained on the 2000 μM proline medium. No significant differences in survival and regrowth were observed for non-frozen explants subjected to pretreatment without LN exposure. A slightly enhancing effect (although non-significant) on post-cryopreservation survival was observed for explants derived from shoots developed on 50 or 500 μM proline, but no significant improvement of regrowth percentage was observed for these two conditions. Although a slight increase in survival could be observed, no significant beneficial effect of proline pretreatment on post-cryoconservation regrowth could be evidenced in our conditions. However, the 2-week period before explant excision could have allowed at least partial metabolism and catabolism of exogenous proline;the results observed could thus have been the consequence of complex interactions. Shorter proline treatments applied closer to the actual LN exposure step might produce different results and allow for clearer interpretation.展开更多
Double haploid production is the most effective way to create true-breeding lines in a single generation.In Arabidopsis,haploid induction via mutation of the centromere-specific histone H3(cenH3)has been shown when th...Double haploid production is the most effective way to create true-breeding lines in a single generation.In Arabidopsis,haploid induction via mutation of the centromere-specific histone H3(cenH3)has been shown when the mutant is outcrossed to the wild-type,and the wild-type genome remains in the haploid progeny.However,factors that affect haploid induction are still poorly understood.Here,we report that a mutant of the cenH3 assembly factor Kinetochore Null2(KNL2)can be used as a haploid inducer when pollinated by the wild-type.We discovered that short-term temperature stress of the knl2 mutant increased the efficiency of haploid induction 10-fold.We also demonstrated that a point mutation in the CENPC-k motif of KNL2 is sufficient to generate haploid-inducing lines,suggesting that haploidinducing lines in crops can be identified in a naturally occurring or chemically induced mutant population,avoiding the generic modification(GM)approach at any stage.Furthermore,a cenh3-4 mutant functioned as a haploid inducer in response to short-term heat stress,even though it did not induce haploids under standard conditions.Thus,we identified KNL2 as a new target gene for the generation of haploid-inducer lines and showed that exposure of centromeric protein mutants to high temperature strongly increases their haploid induction efficiency.展开更多
Plants adjust their development in relation to the availability of nutrient sources. This necessitates signal- ing between root and shoot. Aside from the well-known systemic signaling processes mediated by auxin, cyto...Plants adjust their development in relation to the availability of nutrient sources. This necessitates signal- ing between root and shoot. Aside from the well-known systemic signaling processes mediated by auxin, cytokinin, and sugars, new pathways involving carotenoid-derived hormones have recently been identified. The auxin-responsive MAX pathway controls shoot branching through the biosynthesis of strigolactone in the roots. The BYPASSI gene affects the production of an as-yet unknown carotenoid-derived substance in roots that promotes shoot development. Novel local and systemic mechanisms that control adaptive root development in response to nitrogen and phosphorus starvation were recently discovered. Notably, the ability of the NITRATE TRANSPORTER 1.1 to transport auxin drew for the first time a functional link between auxin, root development, and nitrate availability in soil. The study of plant response to phos- phorus starvation allowed the identification of a systemic mobile miRNA. Deciphering and integrating these signaling pathways at the whole-plant level provide a new perspective for understanding how plants regulate their development in response to environmental cues.展开更多
One key factor defining root system architecture is root branching,i.e.,the process of the formation of new root axes,called lateral roots(LRs),from an existing root.In the model plant Arabidopsis thaliana,LRs origina...One key factor defining root system architecture is root branching,i.e.,the process of the formation of new root axes,called lateral roots(LRs),from an existing root.In the model plant Arabidopsis thaliana,LRs originate from preselected pericycle cells that divide to create an LR primordium(LRP)that grows and eventually forms a new root apical meristem(Banda et al.,2019).During this developmental process,cell-fate acquisition is very plastic and depends on positional information rather than on cell lineage(Banda et al.,2019).Importantly,LR formation occurs inside the parent root,and the LRP must grow through overlying tissues before emerging into the soil.This LR emergence process is controlled by dynamic intercellular signaling and involves a tight coordination of cellular responses in the LRP and surrounding tissues(Banda et al.,2019).In particular,the growing LRP rapidly pushes against the overlying endodermis,a layer of cells mechanically reinforced by the Casparian strip.The crossing of the endodermis by the LRP between stagesⅣand V has been proposed as an important developmental checkpoint during LR development(Banda et al.,2019).展开更多
Dear Editor The NAC (for NO APICAL MERISTEM [NAM], Arabidopsis TRANSCRII^TION ACTIVATOR FACTOR [ATAF] and CUP- SHAPED COTYLEDON [CUC]) proteins are one of the largest families of plant-specific transcription factors...Dear Editor The NAC (for NO APICAL MERISTEM [NAM], Arabidopsis TRANSCRII^TION ACTIVATOR FACTOR [ATAF] and CUP- SHAPED COTYLEDON [CUC]) proteins are one of the largest families of plant-specific transcription factors (Nagata et aL, 2015). They are involved in many different biological processes including development and the response to biotic and abiotic stresses. To date, NAC transcription factors have only been identified in land plants (Zhu et al., 2012; Nagata et al., 2015); and some of them control land-plant-specific processes, such as the formation of specialized water-conducting systems (Xu et al., 2014). Therefore, it has been suggested that their appearance accompanied the emergence of land plants. Here, we exploited the transcriptomic data generated within the 1000 plants project (www.onekp.com, Wickett et al., 2014) to revisit the origin of NAC proteins. Our careful analysis shows that NAC transcription factors appeared before the ernergence of land plants as we detected their homologs in several groups of streptophyte green algae. The possible significance of this finding is discussed.展开更多
Stomatal conductance(gs)is a crucial component of plant physiology,as it links plant productivity and water loss through transpiration.Estimating gs indirectly through leaf temperature(Tl)measurement is common for red...Stomatal conductance(gs)is a crucial component of plant physiology,as it links plant productivity and water loss through transpiration.Estimating gs indirectly through leaf temperature(Tl)measurement is common for reducing the high labor cost associated with direct gs measurement.However,the relationship between observed Tl and gs can be notably affected by local environmental conditions,canopy structure,measurement scale,sample size,and gs itself.展开更多
文摘Short Retraction Notice The paper does not meet the standards of "Advances in Bioscience and Biotechnology". This article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's Retraction Guidelines. The aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused. Editor guiding this retraction: Prof. Abass Alavi (EiC of ABB). Please see the article page for more details. The full retraction notice in PDF is preceding the original paper which is marked "RETRACTED".
文摘Interpretation of primary growth markers (modules) is neglected in sustainable resource management processes, yet it opens up prospects for long time series on tree crown development, necessary for their characterization in the current context of climate change. This study aimed to assess the morphological variation of crown shoots in <i><span style="font-family:Verdana;">Parkia biglobosa</span></i><span style="font-family:Verdana;"> in the face of a changing environment. Axis growth modules of 420 individuals of different ages were retrospectively analyzed in the presence or absence of shading during the wet and dry seasons in seven localities in Cote d’Ivoire. The results showed that the developmental environment of individuals did not influence the growth modules dimensions (P > 0.05). However, module size remained significantly different between locations (P < 0.05). The southern part of the gradient is still favourable and has priority for the establishment of permanent plots. The modules morphology differs from the youngest to the oldest individuals (P < 0.05). The rainy season remains the ideal period for the implementation of agroforestry reforestation programmes based on this species (P < 0.05). </span><i><span style="font-family:Verdana;">Parkia biglobosa</span></i><span style="font-family:Verdana;"> is a monochasial sympod (Pseudo-monopod) with a relay axis that follows the Paul Champagnat architectural model in the young stage, and transits to the Wilhelm Troll model later in the adult and old stage. This information contributes to the understanding of the functioning of crown and the adaptation of this species to a varying environment. It could guide choice of suitable environment and ideal genotype for the implementation of a reforestation or agroforestry programme based on </span><i><span style="font-family:Verdana;">Parkia biglobosa</span></i><span style="font-family:Verdana;">.</span>
文摘In this work we compared the effect of the growth regulator content of the culture medium on the growth of in vitro shoot tips of five yam accessions belonging to four yam species (one Dioscorea alata, one D. rotundata, one D. cayenensis and two D. trifida). Medium S contained 0.6 μM benzyl adenine, 1.07 μM naphthalene acetic acid and 0.23 μM gibberellic acid while medium EBR contained 0.23 μM gibberellic acid and 0.1 μM 24-epibrassinolide. After 2 months of culture, oxidation level was significantly reduced on medium EBR compared to medium S for four of the five accessions tested. By contrast, medium EBR did not have any positive effect on shoot length since length of shoots produced after 2 months of culture on medium S and EBR were similar, except with accession 3-45T, for which shoot length was shorter on medium S compared to medium EBR. These results underline the potential of 24-epibrassinolide to reduce oxidation phenomena during in vitro culture and call for its utilization for regeneration of cryopreserved yam shoot tips, which is often impeded by oxidation phenomena.
文摘The rapid rate of deforestation in Cote d’Ivoire has led to loss of plant species diversity and also threatens some commercial tree species with extinction.Some reforestation and aff orestation has been completed.However,for some species,the numbers of surviving transplants has declined.Hence,it is necessary to develop properly adapted and resilient genotypes that can eff ectively support the programs of forest restoration.In this context we evaluated the eff ects of the provenances of seeds and of various treatments on the germination rates and on plant growth of four commercial trees species(Pycnanthus angolensis,Terminalia superba,Mansonia altissima and Pterygota macrocarpa).We analyzed these parameters for seeds of three provenances(Daloa,Akoupéand Daoukro)of four species and for thirty plants aged 6 months per provenance.Time to begin germination and time to reach maximum germination were similar among species,and were not infl uenced by either treatment or provenance.Untreated seeds and those soaked for 24 and 48 h in water at room temperature yielded the highest germination rates,irrespective of species or provenance.The one exception was P.angolensis,for which no germination was recorded.Within species,some provenances produced higher germination percentages than did others.No clear relationship was computed between the germination rate and the morphometric characteristics of the seeds which varied signifi cantly between provenances.Plant growth and morphological variability also depended greatly on provenance.Genetic factors might be implicated,therefore provenance trials should be undertaken and evaluated.Furthermore,molecular analysis should be undertaken to confi rm the implications of genetic factors and allow for genetic selection.
文摘Uncaria tomentosa presents tomentum that resembles cat’s claws, hence its common name, is a plant that produces various secondary metabolites that are traditionally used in alternative medicine. The natural distribution of this species has been affected by indiscriminate harvesting from its habitat. In the present research, cryopreservation (liquid nitrogen, LN, -196°C) was evaluated as an option for ex situ conservation of this species. The following techniques were evaluated: vitrification and encapsulation-dehydration of apices, vitrification of cell suspensions, and seed desiccation and vitrification. Preculture conditions and exposure times to LS and PVS2 were evaluated. Apex survival was the highest (82%) with preculture in 0.25 M sucrose followed by incubation for 20 and 30 min in LS and PVS2, respectively, prior to cooling in LN. The encapsulation-dehydration technique was evaluated by using sucrose preculture and different capsule moisture contents. Survival of apices cooled in LN was not significantly different between treatments and varied from 31.8% to 52.9% for capsule moisture contents between 22.7% and 20.3%. For cell suspensions precultured in 0.5 M sucrose, cell multiplication and formation of calli with very good appearance were observed in 61.1% of the cultures following vitrification. For cryopreservation of seeds, germination was 89.5% using the desiccation technique and 67.6% to78.1% using vitrification.
文摘Jatropha curcas is a species with a variety of uses. It is grown primarily for oil for biodiesel, but also has agronomic and medicinal applications. Two methods were evaluated for cryopreservation of seeds and zygotic embryos of J. curcas: desiccation followed by rapid immersion of seeds and embryos in liquid nitrogen (LN, -196°C), and vitrification of zygotic embryos. Prior to cryo-preservation, seeds were manually scarified and the moisture content (MC) of seeds and embryos was determined. Explants were disinfected after cryopreservation. Seed germination after LN exposure was 100%. Plantlet development was better in sand substrate than that in vitro. Survival of zygotic embryos after cryopreservation was also 100%, without significant differences between treatments. Optimal development (100%) and plantlet length (51.77 mm) were observed with embryos dried for 60 min to 9.4% MC under laminar flow prior to cryopreservation. Zygotic embryos subjected to the vitrification procedure did not withstand LN exposure. Survival data for non-cryopreserved embryos after each step of the vitrification procedure provided information about embryo tolerance to cryoprotectants.
文摘Many publications describe cryopreservation techniques but only a few studies have focused on the biochemical and physiological changes occurring in plants regenerated from seeds exposed to liquid nitrogen. This paper aims at describing the effect of common bean seed cryostorage on mineral nutrition of young plantlets. The following elements were measured on leaves of 10-day-old plantlets from non-cryopreserved and cryopreserved seeds: Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, S, Se, Sr and Zn. At 10 days after sowing, both treatments (control and cryopreserved seeds) showed 100% seed germination without any visual phenotypic difference. However, contents of several elements in the leaves were different. Exposure of seeds to liquid nitrogen decreased Cu, Cd and Na uptake and increased absorption of B and Al. Further studies are required to understand the mechanisms underlying the relationship between seed exposure to liquid nitrogen and mineral nutrition during the early stages of plantlet growth.
文摘The date palm (Phoenix dactylifera L.), a dioecious species, is of particular interest in the Sahel due to its phenological plasticity in relation to climate change and its double-flowering capacity. This article explores local practices and knowledge associated with date palm cultivation in the oasis basins of southeastern Niger, and provides an inventory of local seed propagated varieties, for more effectively guiding agricultural research and the breeding of this species. We carried out a survey of 30 date palm growers in 14 villages of the Manga region. The qualitative data of the survey were processed by a Multiple Correspondence Analysis. We inventoried 19 date palm varieties, for which the main distinctive criterion was fruit colour, but some other criteria such as biology or provenance were also used. The cultural practices and knowledge associated with the date palm in Manga have improved since the 1990s. They also depend on ethnic groups and the importance they assign to farming compared to livestock rearing and trading activities. The type of basin (high, intermediate, or low water table) influences growers’ practices and perceptions. Lastly, the date harvest in the wet season is abundant, but of mediocre quality, whereas it is the opposite for the dry season harvest. To conclude, sustainable development of date palm cultivation in the Sahel zone relies firstly on the selection of varieties that are early fruit producers or that can complete fruit maturation during the raining season and secondly on technical capacity building for producers.
基金This work has been supported by grants from the French Ministry of Foreign Affairs(Z.Marković)from ARCAD,a flagship programme of Agropolis Fondation(Montpellier,France)(I.Engelmann-Sylvestre).
文摘Proline has been shown to accumulate in plants in response to biotic and abiotic stresses. Exogenous proline has thus been used for improving some plant cryopreservation protocols. Further enhancement of cryopreservation efficiency for in vitro grapevines could be expected if stresses linked to cryopreservation procedures could be reduced. We therefore studied the possible beneficial effect of proline in grapevine cryopreservation. Single-node explants from in vitro grown grapevine plantlets (Vitis vinifera L. cv Portan) were cultured on shooting media (half-strength MS + 1 μM BAP) containing no proline (control) or 50, 500, or 2000 μM filter-sterilized L-proline. Shoot tips excised from these microshoots were subjected to a PVS2-based droplet-vitrification procedure. Control and rewarmed explants were grown on a recovery medium containing 1 μM BAP. Shoot development on control medium and lower proline concentrations did not notably differ whereas the highest concentration of proline inhibited shoot development. Carry-over effects were observed since lower survival and regrowth were obtained both for non-frozen or LN-treated explants excised from micro-shoots obtained on the 2000 μM proline medium. No significant differences in survival and regrowth were observed for non-frozen explants subjected to pretreatment without LN exposure. A slightly enhancing effect (although non-significant) on post-cryopreservation survival was observed for explants derived from shoots developed on 50 or 500 μM proline, but no significant improvement of regrowth percentage was observed for these two conditions. Although a slight increase in survival could be observed, no significant beneficial effect of proline pretreatment on post-cryoconservation regrowth could be evidenced in our conditions. However, the 2-week period before explant excision could have allowed at least partial metabolism and catabolism of exogenous proline;the results observed could thus have been the consequence of complex interactions. Shorter proline treatments applied closer to the actual LN exposure step might produce different results and allow for clearer interpretation.
基金supported by the German Federal Ministry of Education and Research(Plant 2030,Project 031B0192NN,HaploTools)the Deutsche Forschungsgemeinschaft(LE2299/3-1 and LE2299/5-1)the European Regional Development Fund-Project"REMAP"(CZ.02.1.01/0.0/0.0/15_003/0000479)to K.R.
文摘Double haploid production is the most effective way to create true-breeding lines in a single generation.In Arabidopsis,haploid induction via mutation of the centromere-specific histone H3(cenH3)has been shown when the mutant is outcrossed to the wild-type,and the wild-type genome remains in the haploid progeny.However,factors that affect haploid induction are still poorly understood.Here,we report that a mutant of the cenH3 assembly factor Kinetochore Null2(KNL2)can be used as a haploid inducer when pollinated by the wild-type.We discovered that short-term temperature stress of the knl2 mutant increased the efficiency of haploid induction 10-fold.We also demonstrated that a point mutation in the CENPC-k motif of KNL2 is sufficient to generate haploid-inducing lines,suggesting that haploidinducing lines in crops can be identified in a naturally occurring or chemically induced mutant population,avoiding the generic modification(GM)approach at any stage.Furthermore,a cenh3-4 mutant functioned as a haploid inducer in response to short-term heat stress,even though it did not induce haploids under standard conditions.Thus,we identified KNL2 as a new target gene for the generation of haploid-inducer lines and showed that exposure of centromeric protein mutants to high temperature strongly increases their haploid induction efficiency.
文摘Plants adjust their development in relation to the availability of nutrient sources. This necessitates signal- ing between root and shoot. Aside from the well-known systemic signaling processes mediated by auxin, cytokinin, and sugars, new pathways involving carotenoid-derived hormones have recently been identified. The auxin-responsive MAX pathway controls shoot branching through the biosynthesis of strigolactone in the roots. The BYPASSI gene affects the production of an as-yet unknown carotenoid-derived substance in roots that promotes shoot development. Novel local and systemic mechanisms that control adaptive root development in response to nitrogen and phosphorus starvation were recently discovered. Notably, the ability of the NITRATE TRANSPORTER 1.1 to transport auxin drew for the first time a functional link between auxin, root development, and nitrate availability in soil. The study of plant response to phos- phorus starvation allowed the identification of a systemic mobile miRNA. Deciphering and integrating these signaling pathways at the whole-plant level provide a new perspective for understanding how plants regulate their development in response to environmental cues.
基金Research in the authors'lab is supported by the ANR projects NewRoot(no.ANR-17-CE13-0004 to S.G.)caLIPSO(ANR-18-CE13-0025 to Y.B.).
文摘One key factor defining root system architecture is root branching,i.e.,the process of the formation of new root axes,called lateral roots(LRs),from an existing root.In the model plant Arabidopsis thaliana,LRs originate from preselected pericycle cells that divide to create an LR primordium(LRP)that grows and eventually forms a new root apical meristem(Banda et al.,2019).During this developmental process,cell-fate acquisition is very plastic and depends on positional information rather than on cell lineage(Banda et al.,2019).Importantly,LR formation occurs inside the parent root,and the LRP must grow through overlying tissues before emerging into the soil.This LR emergence process is controlled by dynamic intercellular signaling and involves a tight coordination of cellular responses in the LRP and surrounding tissues(Banda et al.,2019).In particular,the growing LRP rapidly pushes against the overlying endodermis,a layer of cells mechanically reinforced by the Casparian strip.The crossing of the endodermis by the LRP between stagesⅣand V has been proposed as an important developmental checkpoint during LR development(Banda et al.,2019).
文摘Dear Editor The NAC (for NO APICAL MERISTEM [NAM], Arabidopsis TRANSCRII^TION ACTIVATOR FACTOR [ATAF] and CUP- SHAPED COTYLEDON [CUC]) proteins are one of the largest families of plant-specific transcription factors (Nagata et aL, 2015). They are involved in many different biological processes including development and the response to biotic and abiotic stresses. To date, NAC transcription factors have only been identified in land plants (Zhu et al., 2012; Nagata et al., 2015); and some of them control land-plant-specific processes, such as the formation of specialized water-conducting systems (Xu et al., 2014). Therefore, it has been suggested that their appearance accompanied the emergence of land plants. Here, we exploited the transcriptomic data generated within the 1000 plants project (www.onekp.com, Wickett et al., 2014) to revisit the origin of NAC proteins. Our careful analysis shows that NAC transcription factors appeared before the ernergence of land plants as we detected their homologs in several groups of streptophyte green algae. The possible significance of this finding is discussed.
基金financially supported by the Bill and Melinda Gates Foundation,Project ID:INV-002830USDA NIFA Hatch project 7003146.
文摘Stomatal conductance(gs)is a crucial component of plant physiology,as it links plant productivity and water loss through transpiration.Estimating gs indirectly through leaf temperature(Tl)measurement is common for reducing the high labor cost associated with direct gs measurement.However,the relationship between observed Tl and gs can be notably affected by local environmental conditions,canopy structure,measurement scale,sample size,and gs itself.