vavilovВавиловский журнал генетики и селекцииVavilov Journal of Genetics and Breeding2500-3259Institute of Cytology and Genetics of Siberian Branch of the RAS10.18699/VJGB-22-19vavilov-3291Research ArticleГЕНЕТИКА И БИОТЕХНОЛОГИЯ РАСТЕНИЙРегуляция дельта-орнитинаминотрансферазы Arabidopsis thaliana в развитии и в ответ на гормоныDevelopmental and hormonal regulation of Arabidopsis thaliana ornithine-delta-aminotransferasehttps://orcid.org/0000-0002-6745-3077ЕгороваА. А.EgorovaA. A.

Новосибирск

Novosibirsk

egorova@bionet.nsc.ruhttps://orcid.org/0000-0001-8626-1831ГерасимоваС. В.GerasimovaS. V.

Новосибирск

Novosibirsk

https://orcid.org/0000-0003-3151-5181КочетовА. В.KochetovA. V.

Новосибирск

Novosibirsk

Федеральный исследовательский центр Институт цитологии и генетики Сибирского отделения Российской академии наук; Новосибирский национальный исследовательский государственный университетРоссияInstitute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences; Novosibirsk State UniversityRussian Federation202204042022262153158Copyright © Егорова А.А., Герасимова С.В., Кочетов А.В., 20222022Егорова А.А., Герасимова С.В., Кочетов А.В.Egorova A.A., Gerasimova S.V., Kochetov A.V.This work is licensed under a Creative Commons Attribution 4.0 License.https://vavilov.elpub.ru/jour/article/view/3291

Фермент орнитинаминотрансфераза (OAT) катализирует перенос дельта-аминогруппы от L-орнитина на альфа-кетоглутарат. В растениях эта реакция связывает цикл мочевины, пролина и путь биосинтеза пролина. В литературе активность OAT связывают с ответом на биотические и абиотические стрессы, метаболизмом азота, но физиологическая роль этого фермента до сих пор остается неясной. В нашем исследовании мы изучали транскрипционную регуляцию гена OAT в Arabisopsis thaliana в нормальных условиях и в ответ на различные ростовые регуляторы. Репортерная конструкция, содержащая ген β-глюкуронидазы (gus) Escherichia coli под контролем промотора гена OAT из A. thaliana была интродуцирована в геном растений A. thaliana. Активность GUS оценивалась в различных экспериментальных условиях, включающих воздействие гормонов, низких и высоких содержаний азота, солевой стресс. Для выявления активности GUS мы использовали гистохимический метод, растения обрабатывали раствором, содержащим X-Gluc. В нормальных условиях промотор был активен при прорастании семени и в развивающихся пестиках и пыльниках. Промотор гена OAT специфично активируется в ответ на различные формы ауксина (IAA, NAA, 2,4D), цитокинина (6-BAP), предшественника этилена (ACC), высокие концентрации азота и NaCl. Результаты анализа экспрессии гена ОАТ соответствуют наблюдаемому паттерну активности промотора, полученному с использованием репортерной системы GUS. Экспрессия гена OAT значимо повышалась в четырехдневных проростках и в ответ на ауксины и цитокинины. При анализе структуры промотора гена OAT обнаружены цис-элементы, связанные с ответами на ауксин и абиотические стрессы. Наши результаты позволяют сделать вывод о связи гена ОАТ с процессами развития растений и о его регуляции ауксинами и цитокининами.

Ornithine aminotransferase (OAT) catalyzes transfer of the delta-amino group from L-ornithine to oxo-glutarate. In plants, this reaction biochemically connects urea cycle, proline cycle, and polyamine biosynthesis pathway. OAT activity is shown to be associated with biotic and abiotic stress responses and nitrogen metabolism, but its physiological role is still unclear. In our study, we decided to investigate transcriptional regulation of the OAT gene in Arabidopsis thaliana under normal conditions and in response to various growth regulators. In the present work, the reporter gene construct containing the Escherichia coli β-glucuronidase gene (gus) under control of the A. thaliana OAT gene promoter was introduced into the genome of A. thaliana ecotype Columbia plants using the floral dip method; GUS activity was assayed in different experimental conditions including hormone treatment, low and high nitrogen and salinity. The GUS activity was analyzed histochemically. Plants were incubated with staining solution containing X-Gluc. We show that under standard growth conditions, the promoter is active during germination and in developing floral organs. OAT promoter activity specifically activates in response to different forms of auxin (IAA, NAA, and 2,4D), cytokinin (6- BAP), ethylene precursor (ACC), high nitrogen and salinity. Analysis of the OAT expression by qRT-PCR confirmed the pattern observed using the GUS reporter system. The OAT gene showed a significantly elevated expression in fourday- old seedlings and in plant roots in response to auxins and cytokinins. The analysis of the OAT promoter structure reveals cis-acting regulatory DNA elements associated with auxin regulation and abiotic stresses. The results of the study indicate that the OAT gene is involved in developmental processes and is regulated by auxin and cytokinins.

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The authors declare that there are no conflicts of interest present.