Abacwaningi abavela eMnyangweni we-Biochemistry e-Indian Institute of Sciences (IISc) bathole indlela esetshenziswa isikhathi eside yizitshalo zasendulo ezifana ne-bryophytes (kufaka phakathi ama-mosses nama-liverworts) ukuzelawula ukukhula kwezitshalo– indlela ephinde yalondolozwa ezitshalweni eziqhakazayo ezisanda kuthuthukiswa.
Lolu cwaningo, olushicilelwe kumagazini i-Nature Chemical Biology, lugxile ekulawulweni okungeyona eyakudala kweprotheyini ye-DELLA, umlawuli wokukhula oyinhloko ongavimbela ukuhlukana kwamaseli ezitshalweni ezisakhula (izitshalo zomhlaba).
"IDELLA isebenza njenge-speed bump, kodwa uma le speed bump ikhona njalo, isitshalo asikwazi ukunyakaza," kuchaza uDebabrata Laha, uprofesa ohlangene we-biochemistry kanye nombhali ohlangene walolu cwaningo. Ngakho-ke, ukuwohloka kwamaprotheni e-DELLA kubalulekile ekukhuthazeni ukukhula kwezitshalo. Ezitshalweni eziqhakazayo, i-DELLA iyonakaliswa lapho i-phytohormonei-gibberellin (GA)ibopha kwi-receptor yayo i-GID1, yakha i-GA-GID1-DELLA complex. Ngemva kwalokho, iphrotheni yokucindezela i-DELLA ibopha kumaketanga e-ubiquitin futhi yonakaliswa yi-26S proteasome.
Ngokuthakazelisayo, ama-bryophyte ayephakathi kwezitshalo zokuqala ukuhlala ezweni, cishe eminyakeni eyizigidi ezingu-500 edlule. Nakuba ekhiqiza i-phytohormone gibberellin (GA), ayinayo i-GID1 receptor. Lokhu kuphakamisa umbuzo: ukukhula nokuthuthukiswa kwalezi zitshalo zokuqala zomhlaba kwakulawulwa kanjani?
Abacwaningi basebenzise uhlelo lwe-CRISPR-Cas9 ukuze basuse i-VIH gene ehambisanayo, ngaleyo ndlela beqinisekisa indima ye-VIH. Izitshalo ezingenayo i-enzyme ye-VIH esebenzayo zibonisa amaphutha amakhulu okukhula nokuthuthukiswa kanye nokukhubazeka kokwakheka, njenge-dense thallus, ukukhula kwe-radial okuphazamisekile, kanye nokuntuleka kwe-calyx. La maphutha alungiswa ngokushintsha i-genome yesitshalo ukuze kukhiqizwe ukuphela okukodwa kuphela (i-N-terminus) ye-enzyme ye-VIH. Besebenzisa amasu athuthukile e-chromatography, ithimba locwaningo lithole ukuthi i-N-terminus iqukethe isizinda se-kinase esikhuthaza ukukhiqizwa kwe-InsP₈.
Abacwaningi bathole ukuthi i-DELLA ingenye yezinhloso zamaseli ze-VIH kinase. Ngaphezu kwalokho, baqaphele ukuthi uhlobo lwezitshalo ezingenayo i-MpVIH lwalufana nolwezitshalo ze-Miscanthus multiforme ezinokwanda kokubonakaliswa kwe-DELLA.
"Kulesi sigaba, silangazelela ukuthola ukuthi ukuzinza noma umsebenzi we-DELLA uyathuthukiswa yini ezitshalweni ezingenayo i-MpVIH," kusho uPriyanshi Rana, umfundi weziqu zobudokotela eqenjini locwaningo likaLahey kanye nombhali wokuqala wephepha. Ngokuvumelana nombono wabo, abacwaningi bathole ukuthi ukuvinjelwa kwe-DELLA kubuyisele kakhulu amaphutha okukhula nokuthuthuka ezitshalweni eziguquliwe ze-MpVIH. Lokhu okutholakele kusikisela ukuthi i-VIH kinase ilawula kabi i-DELLA, ngaleyo ndlela ikhuthaze ukukhula nokuthuthuka kwezitshalo.
Abacwaningi bahlanganise izindlela zofuzo, ze-biochemical, kanye neze-biophysical ukuze bachaze indlela i-inositol pyrophosphate elawula ngayo ukuvezwa kweprotheyini ye-DELLA kule bryophyte. Ngokukhethekile, i-InsP₈, ekhiqizwa yi-MpVIH, ibopha iprotheyini ye-MpDELLA, ikhuthaza i-polyubiquitination yayo, okuholela ekuwohlokeni kwale protheyini ecindezelayo yi-proteasome.
Ucwaningo ngeprotheyini ye-DELLA luqala emuva ku-Green Revolution, lapho ososayensi bengazi besebenzisa amandla ayo ukudala izinhlobo ze-semi-dwarf ezikhiqiza kakhulu. Nakuba indlela esebenza ngayo yayingaziwa ngaleso sikhathi, ubuchwepheshe besimanje buye bavumela ososayensi ukuthi basebenzise ukuhlela izakhi zofuzo ukulawula umsebenzi wale protheyini, ngaleyo ndlela bandise ngempumelelo isivuno sezitshalo.
"Ngokukhula kwabantu kanye nokuncipha komhlaba olimekayo, ukwanda kwesivuno sezitshalo kube yinto ebalulekile," kusho uRaha. Njengoba ukuwohloka kwe-DELLA okulawulwa yi-InsP₈ kungasakazeka ezitshalweni ezisakhula, lokhu kutholakala kungavula indlela yokuthuthukiswa kwezitshalo zesizukulwane esilandelayo ezithela kakhulu.
Isikhathi sokuthunyelwe: Okthoba-31-2025