Ana adana sunadaran DELLAmasu kula da ci gabanwaɗanda ke taka muhimmiyar rawa a ci gaban tsirrai don mayar da martani ga siginar ciki da waje. A matsayin masu kula da rikodin bayanai, DELLAs suna ɗaure ga abubuwan rikodin bayanai (TFs) da histone H2A ta hanyar yankin GRAS ɗinsu kuma ana ɗaukar su aiki a kan masu haɓaka. Binciken da aka yi kwanan nan ya nuna cewa kwanciyar hankali na DELLA ana tsara shi ta hanyar fassara ta hanyoyi biyu: polyubiquitination wanda hormone na shuka ke haifarwa.gibberellin, wanda ke haifar da raguwar su cikin sauri, da haɗuwa da ƙananan masu gyara kamar ubiquitin (SUMO), wanda ke ƙara yawan taruwar su. Bugu da ƙari, ayyukan DELLA ana sarrafa su ta hanyar hanyoyin glycosylation guda biyu daban-daban: O-fucosylation yana haɓaka hulɗar DELLA-TF, yayin da gyaran O-linked N-acetylglucosamine (O-GlcNAc) yana hana hulɗar DELLA-TF. Duk da haka, rawar da DELLA phosphorylation ke takawa ba ta da tabbas saboda binciken da aka yi a baya ya nuna sakamako masu karo da juna, tare da wasu suna nuna cewa phosphorylation yana haɓaka ko danne lalacewar DELLA wasu kuma suna nuna cewa phosphorylation ba ya shafar kwanciyar hankalinsu. A nan, mun gano wuraren phosphorylation a cikin GA1-3 repressor (RGA), AtDELLA, wanda aka tsarkake daga Arabidopsis thaliana ta hanyar mass spectrometry kuma ya nuna cewa phosphorylation na peptides RGA guda biyu a cikin yankunan PolyS da PolyS/T yana haɓaka aikin RGA ta hanyar haɓaka haɗin H2A da haɗin RGA tare da masu haɓaka manufa. Abin lura shine, phosphorylation bai shafi hulɗar RGA-TF ko kwanciyar hankali na RGA ba. Bincikenmu ya bayyana wata hanyar kwayoyin halitta wadda phosphorylation ke haifar da aikin DELLA.
Binciken mu na mass spectrometric ya nuna cewa duka Pep1 da Pep2 suna da sinadarin phosphorylation sosai a cikin RGA a cikin asalin Ga1 mara GA. Baya ga wannan binciken, nazarin phosphoproteomic ya kuma bayyana phosphorylation na Pep1 a cikin RGA, kodayake ba a yi nazarin rawar da yake takawa ba tukuna53,54,55. Sabanin haka, ba a riga an bayyana phosphorylation na Pep2 ba tun da za a iya gano wannan peptide ne kawai ta amfani da transgene na RGAGKG. Duk da cewa maye gurbin m1A, wanda ya kawar da phosphorylation na Pep1, ya ɗan rage ayyukan RGA kaɗan a cikin planta, yana da tasirin ƙari lokacin da aka haɗa shi da m2A wajen rage ayyukan RGA (Karin Hoto na 6). Abu mafi mahimmanci, an rage yawan phosphorylation na Pep1 sosai a cikin maye gurbin sly1 da aka inganta a cikin GA idan aka kwatanta da ga1, yana nuna cewa GA yana haɓaka dephosphorylation na RGA, yana rage ayyukansa. Hanyar da GA ke hana phosphorylation na RGA yana buƙatar ƙarin bincike. Wata yuwuwar ita ce ana samun wannan ta hanyar daidaita wani furotin kinase wanda ba a san shi ba. Duk da cewa bincike ya nuna cewa bayyanar furotin kinase CK1 EL1 yana raguwa ta hanyar GA a cikin shinkafa41, sakamakonmu ya nuna cewa maye gurbi mafi girma na homologue na Arabidopsis EL1 (AEL1-4) ba ya rage phosphorylation na RGA. Dangane da sakamakonmu, wani bincike na phosphoproteomic na baya-bayan nan da aka yi ta amfani da layukan da ke nuna yawan bayyanar Arabidopsis AEL da kuma wani nau'in maye gurbi na ael triple bai gano wani furotin na DELLA a matsayin substrates na waɗannan kinases56 ba. Lokacin da muka shirya rubutun, an ruwaito cewa GSK3, kwayar halittar da ke ɗauke da kinase mai kama da GSK3/SHAGY a cikin alkama (Triticum aestivum), na iya phosphorylate DELLA (Rht-B1b)57, kodayake ba a tabbatar da phosphorylation na Rht-B1b ta GSK3 a cikin planta ba. In vitro enzymatic reactions a gaban GSK3 sannan kuma nazarin mass spectrometry ya bayyana wurare uku na phosphorylation da ke tsakanin yankunan DELLA da GRAS na Rht-B1b (Karin Hoto na 3). Sauyawar serine zuwa alanine a dukkan wuraren phosphorylation guda uku ya haifar da raguwar ayyukan Rht-B1b a cikin alkama mai canza halitta, daidai da bincikenmu cewa maye gurbin alanine a cikin Pep2 RGA ya rage ayyukan RGA. Duk da haka, gwaje-gwajen lalacewar furotin a cikin vitro sun ƙara nuna cewa phosphorylation na iya daidaita Rht-B1b57. Wannan ya bambanta da sakamakonmu da ke nuna cewa maye gurbin alanine a cikin Pep2 RGA ba ya canza daidaitonsa a cikin planta. GSK3 a cikin alkama wani tsari ne na furotin mai ƙarancin hankali na brassinosteroid 2 (BIN2) a cikin Arabidopsis 57. BIN2 mai daidaita siginar BR ne mara kyau, kuma BR yana kunna hanyar siginarsa ta hanyar haifar da lalacewar BIN2 58. Mun nuna cewa maganin BR bai rage daidaiton RGA 59 ko matakan phosphorylation a cikin Arabidopsis ba (Karin Hoto na 2), yana nuna cewa da wuya BIN2 ya sami phosphorylation ta RGA.
An yi nazarin dukkan bayanai na adadi ta amfani da Excel, kuma an tantance manyan bambance-bambance ta amfani da gwajin t-test na ɗalibi. Ba a yi amfani da hanyoyin ƙididdiga don tantance girman samfurin kafin a tantance ba. Ba a cire bayanai daga binciken ba; gwajin ba a yi shi ba bisa ka'ida ba; kuma masu binciken sun san da rarrabawa yayin gwajin da kimanta sakamako. An bayar da girman samfura a cikin tatsuniyoyi na adadi da kuma cikin fayilolin bayanai na asali.
Lokacin Saƙo: Afrilu-15-2025