Soluble sugars function not only as the energy and structural blocks supporting plants,but also as osmoregulators and signal molecules during plant adaptation to water deficit.Here,we investigated drought resistance i...Soluble sugars function not only as the energy and structural blocks supporting plants,but also as osmoregulators and signal molecules during plant adaptation to water deficit.Here,we investigated drought resistance in transgenic apple(Malus×domestica)overexpressing MdFRK2,a key gene regulating fructose content and sugar metabolism.There is no obvious phenotypic difference between MdFRK2-overexpressing transgenic plants and WT plants under the well-watered condition.However,the transgenic plants and the grafted plants using MdFRK2-overexpressing rootstock exhibited improved tolerance to drought stress.Overexpression of MdFRK2 significantly promoted the growth of root system under drought stress.RNA sequencing showed that under drought stress,genes involved in sugar metabolism,transcription regulation,signal transduction or hormone metabolism were differentially expressed in MdFRK2 transgenic plants.Consistent with the gene expression profile,the activities of enzyme(SDH,FRK and NI)involved in sugar metabolism in the roots of MdFRK2 transgenic plants were significantly higher than those of untransformed control plants after drought stress.Under drought stress,overexpression of MdFRK2 promoted the accumulation of IAA,and decreased the contents of ABA and CK in apple root system.In conclusion,these results suggest that MdFRK2 can promote the growth of apple roots under drought stress by regulating sugar metabolism and accumulation,hormone metabolism and signal transduction,and then resist drought stress.展开更多
Fructokinase(FRK)is a regulator of fructose signaling in plants and gateway proteins that catalyze the initial step in fructose metabolism through phosphorylation.Our previous study demonstrated that MdFRK2 protein ex...Fructokinase(FRK)is a regulator of fructose signaling in plants and gateway proteins that catalyze the initial step in fructose metabolism through phosphorylation.Our previous study demonstrated that MdFRK2 protein exhibit not only high affinity for fructose,but also high enzymatic activity due to sorbitol.However,genome-wide identification of the MdFRK gene family and their evolutionary dynamics in apple are yet to be reported.A systematic genome-wide analysis in this study identified a total of nine MdFRK gene members,which could phylogenetically be clustered into seven groups.Chromosomal location and synteny analysis of MdFRKs revealed that their expansion in the apple genome is primarily driven by tandem and segmental duplication events.Divergent expression patterns of MdFRKs were observed in four source-sink tissues and at five different apple fruit developmental stages,which suggested their potential crucial roles in the apple fruit development and sugar accumulation.Reverse transcription-quantitative PCR(RT-qPCR)identified candidate NaCl or drought stress responsive MdFRKs,and transgenic apple plants overexpressing MdFRK2 exhibited considerably enhanced salinity tolerance.Our results will be useful for understanding the functions of MdFRKs in the regulation of apple fruit development and salt stress response.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.32001988)the National Natural Science Foundation of Shaanxi Province(Grant No.2020JC-21)+1 种基金the Open Project Program of State Key Laboratory of Crop Stress Biology for Arid Areas(Grant No.CSBAA2020002)the earmarked fund for the China Agriculture Research System(Grant No.CARS-27)。
文摘Soluble sugars function not only as the energy and structural blocks supporting plants,but also as osmoregulators and signal molecules during plant adaptation to water deficit.Here,we investigated drought resistance in transgenic apple(Malus×domestica)overexpressing MdFRK2,a key gene regulating fructose content and sugar metabolism.There is no obvious phenotypic difference between MdFRK2-overexpressing transgenic plants and WT plants under the well-watered condition.However,the transgenic plants and the grafted plants using MdFRK2-overexpressing rootstock exhibited improved tolerance to drought stress.Overexpression of MdFRK2 significantly promoted the growth of root system under drought stress.RNA sequencing showed that under drought stress,genes involved in sugar metabolism,transcription regulation,signal transduction or hormone metabolism were differentially expressed in MdFRK2 transgenic plants.Consistent with the gene expression profile,the activities of enzyme(SDH,FRK and NI)involved in sugar metabolism in the roots of MdFRK2 transgenic plants were significantly higher than those of untransformed control plants after drought stress.Under drought stress,overexpression of MdFRK2 promoted the accumulation of IAA,and decreased the contents of ABA and CK in apple root system.In conclusion,these results suggest that MdFRK2 can promote the growth of apple roots under drought stress by regulating sugar metabolism and accumulation,hormone metabolism and signal transduction,and then resist drought stress.
基金supported by the Yunnan Provincial Science and Technology Department Agriculture Joint Project,China(202301BD070001-020)。
文摘Fructokinase(FRK)is a regulator of fructose signaling in plants and gateway proteins that catalyze the initial step in fructose metabolism through phosphorylation.Our previous study demonstrated that MdFRK2 protein exhibit not only high affinity for fructose,but also high enzymatic activity due to sorbitol.However,genome-wide identification of the MdFRK gene family and their evolutionary dynamics in apple are yet to be reported.A systematic genome-wide analysis in this study identified a total of nine MdFRK gene members,which could phylogenetically be clustered into seven groups.Chromosomal location and synteny analysis of MdFRKs revealed that their expansion in the apple genome is primarily driven by tandem and segmental duplication events.Divergent expression patterns of MdFRKs were observed in four source-sink tissues and at five different apple fruit developmental stages,which suggested their potential crucial roles in the apple fruit development and sugar accumulation.Reverse transcription-quantitative PCR(RT-qPCR)identified candidate NaCl or drought stress responsive MdFRKs,and transgenic apple plants overexpressing MdFRK2 exhibited considerably enhanced salinity tolerance.Our results will be useful for understanding the functions of MdFRKs in the regulation of apple fruit development and salt stress response.
