Seed viability is an essential feature for genetic resource conservation as well as sustainable crop production.Long-term storage induces seed viability deterioration or seed aging,accompanied by the accumulation of t...Seed viability is an essential feature for genetic resource conservation as well as sustainable crop production.Long-term storage induces seed viability deterioration or seed aging,accompanied by the accumulation of toxic reactive oxygen species(ROS)to suppress seed germination.Controlled deterioration treatment(CDT)is a gen-eral approach for mimicking seed aging.The transcription factor ANAC089 was previously reported to modulate seed primary germination.In this study,we evaluated the ability of ANAC089 to control seed viability during aging.Compared with that in the wild-type line,the mutation of ANAC089 significantly increased H_(2)O_(2),thereby reducing seed viability after CDT,while the overexpression of ANAC089 reduced H_(2)O_(2) and improved seed long-evity,indicating a critical role for ANAC089 in maintaining seed viability through H_(2)O_(2) signaling.A series of stu-dies have shown that ANAC089 targets and negatively regulates the level of ABI5,an important transmitter of abscisic acid(ABA)signals,to affect seed viability after CDT.Furthermore,ABI5 negatively regulated the expres-sion of VTC2,which is involved in the biosynthesis of the antioxidant ascorbic acid and H_(2)O_(2) scavenging.As a result,ANAC089 attenuates the generation of H_(2)O_(2),thereby enhancing seed viability through the ABI5-VTC2 module during the seed aging process.Taken together,our results reveal a novel mechanism by which ANAC089 enhances seed viability by coordinating ABI5 and VTC2 expression,ultimately preventing the overac-cumulation of H_(2)O_(2),which would have led to reduced seed viability.展开更多
目的探讨ABI家族成员3结合蛋白(ABI family member 3-binding protein,ABI3BP)在血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导内皮祖细胞功能障碍中的作用及机制。方法为探讨ABI3BP在AngⅡ诱导内皮祖细胞功能障碍中的作用,将细胞分为4组,sh-N...目的探讨ABI家族成员3结合蛋白(ABI family member 3-binding protein,ABI3BP)在血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导内皮祖细胞功能障碍中的作用及机制。方法为探讨ABI3BP在AngⅡ诱导内皮祖细胞功能障碍中的作用,将细胞分为4组,sh-NC组[转染阴性对照短发夹RNA(LV-scramble-shRNA)+磷酸盐缓冲液(phosphate buffered saline,PBS)]、sh-ABI3BP组[转染ABI3BP shRNA(LV-ABI3BP-shRNA)+PBS]、sh-NC+AngⅡ组(LV-scramble-shRNA+AngⅡ)和sh-ABI3BP+AngⅡ组(LV-ABI3BP-shRNA+AngⅡ)。采用Transwell实验检测细胞迁移能力,黏附实验检测细胞黏附能力,Matrigel检测细胞成管能力,原位末端标记法检测细胞凋亡。Western blot检测整合素β1-黏着斑激酶(focal adhesion kinase,FAK)-P53信号通路变化情况。结果与sh-NC组比较,sh-NC+AngⅡ组迁移细胞数量、黏附细胞数量、小管形成数量显著降低,细胞凋亡率、整合素β1、磷酸化FAK(p-FAK)/FAK及P53蛋白表达显著增高,差异有统计学意义(P<0.05)。与sh-NC+AngⅡ组比较,sh-ABI3BP+AngⅡ组迁移细胞数量[(88.67±8.33)个vs(62.33±7.37)个]、黏附细胞数量[(104.33±6.03)个vs(68.33±10.05)个]、小管形成数量[(36.33±3.21)个vs(19.33±3.06)个]显著增高,细胞凋亡率、整合素β1、p-FAK/FAK及P53蛋白表达水平显著降低,差异有统计学意义(P<0.05)。结论AngⅡ可上调ABI3BP表达,敲低ABI3BP基因表达可改善AngⅡ诱导的内皮祖细胞功能障碍,其机制可能与抑制整合素β1-FAK-P53信号通路有关。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
基金supported by the National Natural Science Foundation of China(31970289 to X.H.and 32170562 to P.L.).
文摘Seed viability is an essential feature for genetic resource conservation as well as sustainable crop production.Long-term storage induces seed viability deterioration or seed aging,accompanied by the accumulation of toxic reactive oxygen species(ROS)to suppress seed germination.Controlled deterioration treatment(CDT)is a gen-eral approach for mimicking seed aging.The transcription factor ANAC089 was previously reported to modulate seed primary germination.In this study,we evaluated the ability of ANAC089 to control seed viability during aging.Compared with that in the wild-type line,the mutation of ANAC089 significantly increased H_(2)O_(2),thereby reducing seed viability after CDT,while the overexpression of ANAC089 reduced H_(2)O_(2) and improved seed long-evity,indicating a critical role for ANAC089 in maintaining seed viability through H_(2)O_(2) signaling.A series of stu-dies have shown that ANAC089 targets and negatively regulates the level of ABI5,an important transmitter of abscisic acid(ABA)signals,to affect seed viability after CDT.Furthermore,ABI5 negatively regulated the expres-sion of VTC2,which is involved in the biosynthesis of the antioxidant ascorbic acid and H_(2)O_(2) scavenging.As a result,ANAC089 attenuates the generation of H_(2)O_(2),thereby enhancing seed viability through the ABI5-VTC2 module during the seed aging process.Taken together,our results reveal a novel mechanism by which ANAC089 enhances seed viability by coordinating ABI5 and VTC2 expression,ultimately preventing the overac-cumulation of H_(2)O_(2),which would have led to reduced seed viability.
文摘密码子偏性是影响外源基因表达的重要因素,也是反映基因家族进化的关键线索之一。兰科植物是植物保护中的“旗舰”类群,且多数物种具有药用和观赏价值,但种子不易萌发,而ABI3(abscisic acid insensitive 3)基因是ABA信号转导的中心调控因子,是调控植物种子萌发的关键因子。因此,深入研究兰科ABI3基因密码子偏性,可为解析该基因功能、优化密码子组成奠定基础。本研究以拟南芥ABI3基因为探针,从公共数据库(NCBI)筛选出45条兰科植物ABI3基因,通过CodonW、SPSS、MEGA等生物信息学程序对其进行密码子使用模式和偏好性分析。相关参数分析结果表明,该基因的ENC(effective number of codon)值范围分布为40.84~58.46,其中大于52的占82.2%,CAI(codon adaptation index)平均值为0.203,远小于1,表明ABI3基因的密码子偏性相对较弱;中性绘图分析显示,GC12与GC3的回归曲线的斜率为0.6103,R2=0.7928,P<0.05,有极高的相关性,这暗示着碱基组成对密码子偏性具有重要的影响;ENC-plot分析中,所有基因ENC值都低于期望值,但相差不大,说明兰科ABI3基因密码子主要受碱基突变的影响,同时也受选择压力等其他因素影响。奇偶偏好性分析显示,大多数基因分布在平面图的右侧区域,密码子第3位A/T(U)的使用频率高于G/C。通过RSCU和ΔRSCU分析确定了26个最优密码子,其中以A/T(U)结尾的密码子有14个,以T(U)结尾的密码子有10个,说明兰科植物ABI3基因相对偏好使用A/U结尾的密码子,尤其偏好使用T(U)结尾的密码子,这与大多数单子叶植物密码子使用偏好不同。本研究可为兰科植物ABI3基因的系统发育、功能解析、提高ABI3基因表达效率提供理论基础,同时可为促进植物密码子生物学研究及外源基因改良提供参考。
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.
