In developing apple fruit,metabolic compartmentation is poorly understood due to the lack of experimental data.Distinguishing subcellular compartments in fruit using non-aqueous fractionation has been technically diff...In developing apple fruit,metabolic compartmentation is poorly understood due to the lack of experimental data.Distinguishing subcellular compartments in fruit using non-aqueous fractionation has been technically difficult due to the excess amount of sugars present in the different subcellular compartments limiting the resolution of the technique.The work described in this study represents the first attempt to apply non-aqueous fractionation to developing apple fruit,covering the major events occurring during fruit development(cell division,cell expansion,and maturation).Here we describe the non-aqueous fractionation method to study the subcellular compartmentation of metabolites during apple fruit development considering three main cellular compartments(cytosol,plastids,and vacuole).Evidence is presented that most of the sugars and organic acids were predominantly located in the vacuole,whereas some of the amino acids were distributed between the cytosol and the vacuole.The results showed a shift in the plastid marker from the lightest fractions in the early growth stage to the dense fractions in the later fruit growth stages.This implies that the accumulation of starch content with progressing fruit development substantially influenced the distribution of plastidial fragments within the non-aqueous density gradient applied.Results from this study provide substantial baseline information on assessing the subcellular compartmentation of metabolites in apple fruit in general and during fruit growth in particular.展开更多
Sulfate is an essential macronutrient for plants. Plants have developed strategies to cope with sulfate deficiency, and other nutrient ion limitations. However, the regulation of these adaptive responses and the coord...Sulfate is an essential macronutrient for plants. Plants have developed strategies to cope with sulfate deficiency, and other nutrient ion limitations. However, the regulation of these adaptive responses and the coordinating signals that underlie them are still poorly characterized. O-acetylserine （OAS） is a marker metabolite of sulfate starvation and has been speculated to have a signaling function. OAS is synthesized by the enzyme serine acetyltransferase （SERAT）, which is encoded by five distinct genes in Arabidopsis. We investigated quadruple knockout mutants of SERAT that retained only one functional isoform. These mutants displayed symptoms of sulfate starvation. Furthermore, some of them displayed phenotypes typical of prolonged sulfate starvation, in particular, developmental programs associated with senescence or stress responses. Thus, we compared metabolite and transcriptome data from these mutants with N-, P-, K-, and S-depleted plants. This revealed many similarities with general nutrient-depletion-induced senescence （NuDIS）, in- dicating the recruitment of existing regulatory programs for nutrient-starvation responses. Several candidate genes that could be involved in these processes were identified, including transcription factors and other regulatory proteins, as well as the functional categories of their target genes. These results outline components of the regulatory network controlling plant development under sulfate stress, forming a basis for further investigations to elucidate the complete network. In turn, this will advance our broader understanding of plant responses to a range of other nutrient stresses.展开更多
Wind is an environmental stimulus that stresses plants of all growth forms at all life-stages by influencing the development,architecture,and morphology of roots and shoots.However,comparative studies are scarce and n...Wind is an environmental stimulus that stresses plants of all growth forms at all life-stages by influencing the development,architecture,and morphology of roots and shoots.However,comparative studies are scarce and no study directly investigated whether shoot and root morphological traits of trees,grasses and forbs differ in their response to short wind pulses of different wind intensity.In this study,we found that across species,wind stress by short wind pulses of increasing intensity consistently changed root morphology,but did not affect shoot morphological traits,except plant height in four species.Wind effects in roots were generally weak in tree species but consistent across growth forms.Furthermore,plant height of species was correlated with changes in specific root length and average diameter.Our results indicate that short-pulse wind treatments affect root morphology more than shoot morphology across growth forms.They further suggest that wind stress possibly promotes root anchorage in young plants and that these effects might depend on plant height.展开更多
文摘In developing apple fruit,metabolic compartmentation is poorly understood due to the lack of experimental data.Distinguishing subcellular compartments in fruit using non-aqueous fractionation has been technically difficult due to the excess amount of sugars present in the different subcellular compartments limiting the resolution of the technique.The work described in this study represents the first attempt to apply non-aqueous fractionation to developing apple fruit,covering the major events occurring during fruit development(cell division,cell expansion,and maturation).Here we describe the non-aqueous fractionation method to study the subcellular compartmentation of metabolites during apple fruit development considering three main cellular compartments(cytosol,plastids,and vacuole).Evidence is presented that most of the sugars and organic acids were predominantly located in the vacuole,whereas some of the amino acids were distributed between the cytosol and the vacuole.The results showed a shift in the plastid marker from the lightest fractions in the early growth stage to the dense fractions in the later fruit growth stages.This implies that the accumulation of starch content with progressing fruit development substantially influenced the distribution of plastidial fragments within the non-aqueous density gradient applied.Results from this study provide substantial baseline information on assessing the subcellular compartmentation of metabolites in apple fruit in general and during fruit growth in particular.
文摘Sulfate is an essential macronutrient for plants. Plants have developed strategies to cope with sulfate deficiency, and other nutrient ion limitations. However, the regulation of these adaptive responses and the coordinating signals that underlie them are still poorly characterized. O-acetylserine （OAS） is a marker metabolite of sulfate starvation and has been speculated to have a signaling function. OAS is synthesized by the enzyme serine acetyltransferase （SERAT）, which is encoded by five distinct genes in Arabidopsis. We investigated quadruple knockout mutants of SERAT that retained only one functional isoform. These mutants displayed symptoms of sulfate starvation. Furthermore, some of them displayed phenotypes typical of prolonged sulfate starvation, in particular, developmental programs associated with senescence or stress responses. Thus, we compared metabolite and transcriptome data from these mutants with N-, P-, K-, and S-depleted plants. This revealed many similarities with general nutrient-depletion-induced senescence （NuDIS）, in- dicating the recruitment of existing regulatory programs for nutrient-starvation responses. Several candidate genes that could be involved in these processes were identified, including transcription factors and other regulatory proteins, as well as the functional categories of their target genes. These results outline components of the regulatory network controlling plant development under sulfate stress, forming a basis for further investigations to elucidate the complete network. In turn, this will advance our broader understanding of plant responses to a range of other nutrient stresses.
文摘Wind is an environmental stimulus that stresses plants of all growth forms at all life-stages by influencing the development,architecture,and morphology of roots and shoots.However,comparative studies are scarce and no study directly investigated whether shoot and root morphological traits of trees,grasses and forbs differ in their response to short wind pulses of different wind intensity.In this study,we found that across species,wind stress by short wind pulses of increasing intensity consistently changed root morphology,but did not affect shoot morphological traits,except plant height in four species.Wind effects in roots were generally weak in tree species but consistent across growth forms.Furthermore,plant height of species was correlated with changes in specific root length and average diameter.Our results indicate that short-pulse wind treatments affect root morphology more than shoot morphology across growth forms.They further suggest that wind stress possibly promotes root anchorage in young plants and that these effects might depend on plant height.
