摘要
为明晰桃叶片叶绿素生物合成过程中对紫外线B(Ultraviolet B,UV-B)辐照响应的关键步骤,以设施栽培的‘中油5号’油桃(Prunus persica var.nectariana)7年生树为试材,自花后7 d开始,每天8:30—9:30补充适宜剂量(由前期试验筛出,约1.44 k J·m-2·d-1)的UV-B直至果实采收,以正常生长、未补充UV-B辐照的植株为对照,对生育期内叶片叶绿素生物合成过程中前体物质、中间产物和叶绿素含量以及关键酶活性的动态变化进行了探究。结果表明,在叶绿素合成第一阶段中,UV-B辐照通过提升前体物质δ–氨基酮戊酸(ALA)合成关键酶——谷氨酸酯–1–半醛2,1–氨基变位酶(GSA-AM)的活性,增加了ALA的积累量,为生物合成的开始奠定物质基础。在第二阶段中,UV-B提高了胆色素原脱氨酶(PBGD)的活性,促进了羟甲基胆色素原的合成,为后续产物尿卟啉原Ⅲ(UrogenⅢ)的合成提供底物,使得整个生育期内叶片中粪卟啉原Ⅲ(CoprogenⅢ)和原卟啉Ⅸ(ProtoⅨ)的含量显著提升。UV-B辐照后第三阶段的Mg–螯合酶(Mg CH)和Mg–原卟啉Ⅸ单甲基酯环化酶(Mg PEC)等关键酶的活性显著升高,各中间产物Mg–原卟啉Ⅸ(Mg PⅨ)、Mg–原卟啉Ⅸ甲酯(Mg PME)、联乙烯原叶绿素酸酯、原叶绿素酸酯(Pchlide)、叶绿素酸酯a(Chlide a)、叶绿素酸酯b(Chlide b)含量均得到提升,最后产物叶绿素的含量也显著高于对照。可见UV-B辐照影响叶绿素生物合成的主要关键步骤为前体物质ALA的合成、羟甲基胆色素原的合成、UrogenⅢ向CoprogenⅢ的转化、Mg2+插入ProtoⅨ及其后等4个步骤,且对叶绿素生物合成的影响具有长期积累性。
In order to clarify the key steps in the response of chlorophyll(Chl)biosynthesis to ultraviolet B(UV-B)irradiation in greenhouse nectarine leaves,the 7-year-old nectarine‘Zhongyou 5’was used as the test material,which was cultivated in greenhouse from 7 days after flowering.The appropriate dose of UV-B(about 1.44 kJ•m-2•d-1 screened by previous experiments)was supplemented at 8:30—9:30 every morning until the fruit was harvested.The dynamic changes of precursor substances,intermediate product content,Chl content and key enzyme activity in the process of Chl biosynthesis in leaves during the growth and development period were investigated with normal growth and unsupplemented UV-B irradiated plants as the control.The results showed that in the first stage of Chl synthesis,UV-B irradiation increased the accumulation ofδ-aminolevulinic acid(ALA)by increasing the activity of glutamate-1-semialdehyde-2,1-aminomutase(GSA-AM),a key enzyme in the synthesis of precursor ALA,which laid a good material foundation for the beginning of biosynthesis.In the second stage,UV-B increased the activity of bile pigment deaminase(PBGD),promoted the synthesis of hydroxymethyl bile pigment,and provided sufficient substrates for the synthesis of subsequent products uroporphyrinogenⅢ(UrogenⅢ),so that the content of CoprogenⅢand ProtoⅨin leaves increased significantly during the whole growth period.After UV-B irradiation,the activities of key enzymes such as Mg-chelating enzyme(MgCH)and Mg-protoporphyrinⅨmonomethyl ester cyclase(MgPEC)in the third stage were significantly increased,and the content of intermediate products Mg-protoporphyrinⅨ(MgPⅨ),Mg-protoporphyrinⅨmethyl ester(MgPME),bivinyl protochlorophyllate,protochlorophyllate(Pchlide),chlorophyllate a(Chlide a)and chlorophyllate b(Chlide b)were all increased,the chlorophyll content of the product was also significantly higher than that of the control.It can be seen that the main key steps of UV-B irradiation affecting Chl biosynthesis are the synthesis of p
作者
田歌
刘建廷
高传彩
赵雪惠
樊永信
李森
张寒啸
陈修德
李玲
李冬梅
TIAN Ge;LIU Jianting;GAO Chuancai;ZHAO Xuehui;FAN Yongxin;LI Sen;ZHANG Hanxiao;CHEN Xiude;LI Ling;LI Dongmei(Shandong Fruit and Vegetable High Quality and Efficient Production Collaborative Innovation Center,College of Horticultural Science and Engineering,Shandong Agricultural University,Tai’an,Shandong 271018,China;College of Seed and Facility Agricultural Engineering,Weifang University,Weifang,Shandong 261061,China)
出处
《园艺学报》
CAS
CSCD
北大核心
2024年第6期1332-1344,共13页
Acta Horticulturae Sinica
基金
山东省自然科学基金面上项目(ZR2022MC062)。
关键词
油桃
设施栽培
紫外线B
叶绿素
生物合成
nectarine
facility cultivation
UV-B
chlorophyll
biosynthesis
