During production process,the superscript numbers were inadvertently normalised and has been published online with errors.The superscript has been updated in the abstract section,Table 2,Table 3,Table 4 and Table 5.Th...During production process,the superscript numbers were inadvertently normalised and has been published online with errors.The superscript has been updated in the abstract section,Table 2,Table 3,Table 4 and Table 5.The original article has been corrected.展开更多
Firmness is one of the most important fruit quality traits in strawberries.The postharvest shelf life of this soft fruit is highly limited by the loss of firmness,where cell wall disassembly plays an important role.Pr...Firmness is one of the most important fruit quality traits in strawberries.The postharvest shelf life of this soft fruit is highly limited by the loss of firmness,where cell wall disassembly plays an important role.Previous studies demonstrated that the polygalacturonase FaPG1 has a key role in remodelling pectins during strawberry softening.In this study,FaPG1 knockout strawberry plants have been generated using the CRISPR/Cas9 system delivered via Agrobacterium tumefaciens.Ten independent lines,cv.“Chandler”,were obtained,and all of them were successfully edited as determined by PCR amplification and T7 endonuclease assay.The targeted mutagenesis insertion and deletion rates were analyzed using targeted deep sequencing.The percentage of edited sequences varied from 47%up to almost 100%,being higher than 95%for seven of the selected lines.Phenotypic analyses showed that 7 out of the eight lines analyzed produced fruits significantly firmer than the control,ranging from 33 to 70%increase in firmness.There was a positive relationship between the degree of FaPG1 editing and the rise in fruit firmness.Minor changes were observed in other fruit quality traits,such as colour,soluble solids,titratable acidity or anthocyanin content.Edited fruits showed a reduced softening rate during postharvest,displayed a reduced transpirational water loss,and were less damaged by Botrytis cinerea inoculation.The analysis of four potential off-target sites revealed no mutation events.In conclusion,editing the FaPG1 gene using the CRISPR/Cas9 system is an efficient method for improving strawberry fruit firmness and shelf life.展开更多
Screw connection is a type most commonly applied to timber structures.As important commercial tree species in China,Masson pine and Chinese fir have the potential to prepare wood structures.In this study,the effects o...Screw connection is a type most commonly applied to timber structures.As important commercial tree species in China,Masson pine and Chinese fir have the potential to prepare wood structures.In this study,the effects of the diameter of the self-tapping screw and the guiding bores on the nail holding performance on different sections of Masson pine and Chinese fir dimension lumbers were mainly explored.The results showed that:(1)The nail holding strength of the tangential section was the maximum,followed by that of the radial section,and that of the cross section was the minimum.(2)The nail holding strength of Masson pine was higher than that of Chinese fir.(3)The nail holding strength grew with the increase in the diameter of self-tapping screws,but a large diameter would lead to plastic cracking of the timber,thus further affecting the nail holding strength.Masson pine and Chinese fir reached the maximum nail holding strength when the diameter of self-tapping screws was 3.5 mm.(4)Under a large diameter of screws,prefabricated guiding bores could mitigate timber cracking and improve its nail holding strength.(5)Prefabricated guiding bores were more necessary for the screw connection of Masson pine.The results obtained could provide a scientific basis for the screw connection design of Masson pine and Chinese fir timber structures.展开更多
Balsam fir is an important Christmas tree species, especially in eastern Canada. The natural Christmas tree industry faces a challenge in postharvest needle abscission. Though there have been many studies describing t...Balsam fir is an important Christmas tree species, especially in eastern Canada. The natural Christmas tree industry faces a challenge in postharvest needle abscission. Though there have been many studies describing the physiological triggers and consequences in postharvest balsam fir, there have been no studies describing morphological or ultrastructural changes. Therefore, the objective of this study was to examine changes in stomata and chloroplast of postharvest needles. Branches were collected from low and high needle abscission resistance balsam fir genotypes, placed in water, and displayed in typical household conditions for 11 weeks. Needle abscission, chlorophyll fluorescence, and water uptake were monitored throughout. Needles stomata and chloroplasts were examined under a scanning and transmission electron microscope, respectively, each week. All branches had increased abscission, decreased chlorophyll fluorescence, and decreased water uptake over time. Needle surfaces accumulated fungal hyphae, especially in stomata. Chloroplasts demonstrated some dysfunction within two weeks, with notable decreases in chloroplast starch and increases in plastoglobulins. Within several weeks thylakoid membranes had been dismantled as chloroplasts transformed into gerontoplasts. All biophysical and structural changes were more pronounced in low needle abscission resistant genotypes. This research identifies a potential role for needle fungi in postharvest needle abscission and confirms the postharvest senescence of chloroplasts. Though it was previously speculated that chloroplasts must senesce postharvest, this study identifies how quickly this process occurs and that it occurs at different rates in contrasting genotypes.展开更多
文摘During production process,the superscript numbers were inadvertently normalised and has been published online with errors.The superscript has been updated in the abstract section,Table 2,Table 3,Table 4 and Table 5.The original article has been corrected.
基金supported by the Ministerio de Ciencia,Innovación y Universidades and FEDER EU funds(grant numbers AGL2017-86531-C2-1R and PID2020-118468RB-C21)the University of Malaga(grant number B1-2020_09)+1 种基金CS-R was awarded a PhD Fellowship from the Ministerio de Ciencia,Innovación y Universidades(PRE2018-085509)PhD Program Advanced Biotechnology,University of Málaga.
文摘Firmness is one of the most important fruit quality traits in strawberries.The postharvest shelf life of this soft fruit is highly limited by the loss of firmness,where cell wall disassembly plays an important role.Previous studies demonstrated that the polygalacturonase FaPG1 has a key role in remodelling pectins during strawberry softening.In this study,FaPG1 knockout strawberry plants have been generated using the CRISPR/Cas9 system delivered via Agrobacterium tumefaciens.Ten independent lines,cv.“Chandler”,were obtained,and all of them were successfully edited as determined by PCR amplification and T7 endonuclease assay.The targeted mutagenesis insertion and deletion rates were analyzed using targeted deep sequencing.The percentage of edited sequences varied from 47%up to almost 100%,being higher than 95%for seven of the selected lines.Phenotypic analyses showed that 7 out of the eight lines analyzed produced fruits significantly firmer than the control,ranging from 33 to 70%increase in firmness.There was a positive relationship between the degree of FaPG1 editing and the rise in fruit firmness.Minor changes were observed in other fruit quality traits,such as colour,soluble solids,titratable acidity or anthocyanin content.Edited fruits showed a reduced softening rate during postharvest,displayed a reduced transpirational water loss,and were less damaged by Botrytis cinerea inoculation.The analysis of four potential off-target sites revealed no mutation events.In conclusion,editing the FaPG1 gene using the CRISPR/Cas9 system is an efficient method for improving strawberry fruit firmness and shelf life.
基金funded by the National Natural Science Foundation of China (32160348)Forestry Science and Technology Research Project of Guizhou Forestry Bureau (J[2022]21 and[2020]C14)+1 种基金Department Program of Guizhou Province ([2020]1Y128)the Cultivation Project of Guizhou University of China ([2019]37).
文摘Screw connection is a type most commonly applied to timber structures.As important commercial tree species in China,Masson pine and Chinese fir have the potential to prepare wood structures.In this study,the effects of the diameter of the self-tapping screw and the guiding bores on the nail holding performance on different sections of Masson pine and Chinese fir dimension lumbers were mainly explored.The results showed that:(1)The nail holding strength of the tangential section was the maximum,followed by that of the radial section,and that of the cross section was the minimum.(2)The nail holding strength of Masson pine was higher than that of Chinese fir.(3)The nail holding strength grew with the increase in the diameter of self-tapping screws,but a large diameter would lead to plastic cracking of the timber,thus further affecting the nail holding strength.Masson pine and Chinese fir reached the maximum nail holding strength when the diameter of self-tapping screws was 3.5 mm.(4)Under a large diameter of screws,prefabricated guiding bores could mitigate timber cracking and improve its nail holding strength.(5)Prefabricated guiding bores were more necessary for the screw connection of Masson pine.The results obtained could provide a scientific basis for the screw connection design of Masson pine and Chinese fir timber structures.
文摘Balsam fir is an important Christmas tree species, especially in eastern Canada. The natural Christmas tree industry faces a challenge in postharvest needle abscission. Though there have been many studies describing the physiological triggers and consequences in postharvest balsam fir, there have been no studies describing morphological or ultrastructural changes. Therefore, the objective of this study was to examine changes in stomata and chloroplast of postharvest needles. Branches were collected from low and high needle abscission resistance balsam fir genotypes, placed in water, and displayed in typical household conditions for 11 weeks. Needle abscission, chlorophyll fluorescence, and water uptake were monitored throughout. Needles stomata and chloroplasts were examined under a scanning and transmission electron microscope, respectively, each week. All branches had increased abscission, decreased chlorophyll fluorescence, and decreased water uptake over time. Needle surfaces accumulated fungal hyphae, especially in stomata. Chloroplasts demonstrated some dysfunction within two weeks, with notable decreases in chloroplast starch and increases in plastoglobulins. Within several weeks thylakoid membranes had been dismantled as chloroplasts transformed into gerontoplasts. All biophysical and structural changes were more pronounced in low needle abscission resistant genotypes. This research identifies a potential role for needle fungi in postharvest needle abscission and confirms the postharvest senescence of chloroplasts. Though it was previously speculated that chloroplasts must senesce postharvest, this study identifies how quickly this process occurs and that it occurs at different rates in contrasting genotypes.
