Abaphandi abavela kwiSebe leBiochemistry kwi-Indian Institute of Sciences (IISc) bafumanise indlela ekudala ifunwa esetyenziswa zizityalo zasemhlabeni zakudala ezifana ne-bryophytes (kuquka i-mosses kunye ne-liverworts) ukuzelawula ukukhula kwezityalo– indlela ekwalondolozwe kwizityalo ezisandula ukuveliswa iintyatyambo.
Olu phononongo, olupapashwe kwiphephancwadi iNature Chemical Biology, lugxile kulawulo olungelulo olwesiqhelo lweprotheyini yeDELLA, umlawuli wokukhula oyintloko onokuthintela ukwahlukana kweeseli kwizityalo ezisandul’ ukuzalwa (izityalo zomhlaba).
“IDELLA isebenza njenge-speed bump, kodwa ukuba le speed bump ihlala ikhona, isityalo asinakushukuma,” ucacisa uDebabrata Laha, uprofesa oncedisayo we-biochemistry kunye nombhali-mbhali wolu phando. Ke ngoko, ukonakala kweeproteni zeDELLA kubalulekile ekukhuthazeni ukukhula kwezityalo. Kwizityalo ezidubula iintyatyambo, iDELLA iyonakala xa i-phytohormonei-gibberellin (GA)ibopha kwi-receptor yayo i-GID1, yenze i-GA-GID1-DELLA complex. Emva koko, iprotheyini ye-DELLA repressor ibopha kwi-ubiquitin chains kwaye yonakaliswa yi-26S proteasome.
Okubangel’ umdla kukuba, ii-bryophytes zaziphakathi kwezityalo zokuqala ukuhlala emhlabeni, malunga neminyaka eyi-500 yezigidi eyadlulayo. Nangona zivelisa i-phytohormone gibberellin (GA), azinayo i-GID1 receptor. Oku kuphakamisa umbuzo: ukukhula nophuhliso lwezi zityalo zokuqala zomhlaba lwalulawulwa njani?
Abaphandi basebenzise inkqubo yeCRISPR-Cas9 ukucima i-VIH gene ehambelanayo, ngaloo ndlela beqinisekisa indima yeVIH. Izityalo ezingenayo i-enzyme yeVIH esebenzayo zibonisa iziphene ezinzulu zokukhula kunye nophuhliso kunye nokungahambi kakuhle kwesimo somzimba, njenge-dense thallus, ukukhula kwe-radial okungasebenzi kakuhle, kunye nokungabikho kwe-calyx. Ezi ziphene zalungiswa ngokuguqula i-genome yesityalo ukuze kuveliswe isiphelo esinye kuphela (i-N-terminus) ye-enzyme yeVIH. Besebenzisa iindlela eziphambili ze-chromatography, iqela lophando lifumanise ukuba i-N-terminus ine-kinase domain ekhuthaza ukuveliswa kwe-InsP₈.
Abaphandi bafumanise ukuba iDELLA yenye yeethagethi zeseli zeVIH kinase. Ngaphezu koko, baqaphele ukuba uhlobo lwezityalo ezingenayo iMpVIH lwalufana nolwezityalo zeMiscanthus multiforme kunye nokwanda kokubonakaliswa kweDELLA.
“Kweli nqanaba, sinomdla wokufumanisa ukuba ingaba uzinzo okanye umsebenzi weDELLA uyaphucuka na kwizityalo ezingenayo iMpVIH,” utshilo uPriyanshi Rana, umfundi wobugqirha kwiqela lophando likaLahey kunye nombhali wokuqala wephepha. Ngokuhambelana nengcamango yabo, abaphandi bafumanise ukuba ukuthintelwa kweDELLA kubuyisele kakhulu iziphene zokukhula nophuhliso kwizityalo eziguqulweyo zeMpVIH. Ezi ziphumo zibonisa ukuba iVIH kinase iyilawula kakubi iDELLA, ngaloo ndlela ikhuthaza ukukhula nophuhliso lwezityalo.
Abaphandi badibanise iindlela zemfuza, zebhayoloji, kunye nezebhayoloji ukucacisa indlela i-inositol pyrophosphate elawula ngayo ukubonakaliswa kweprotheyini ye-DELLA kule bryophyte. Ngokukodwa, i-InsP₈, eveliswa yi-MpVIH, ibopha kwiprotheyini ye-MpDELLA, ikhuthaza i-polyubiquitination yayo, nto leyo ekhokelela ekuwohlokeni kwale protheyini yokunciphisa umzimba yi-proteasome.
Uphando ngeproteni ye-DELLA luqala kwiNguquko yeGreen, xa izazinzulu bezisebenzisa amandla azo ngokungazi ukwenza iintlobo ze-semi-dwarf ezivelisa kakhulu. Nangona indlela esebenza ngayo yayingaziwa ngelo xesha, ubuchwepheshe banamhlanje buye bavumela izazinzulu ukuba zisebenzise ukuhlelwa kwezakhi zofuzo ukulawula umsebenzi wale proteni, ngaloo ndlela zinyusa ngempumelelo isivuno sesivuno.
“Ngokwanda kwabantu kunye nokuncipha komhlaba olimekayo, ukwanda kwesivuno sezityalo kuye kwaba yinto ebalulekileyo,” utshilo uRaha. Ngenxa yokuba ukonakala kwe-DELLA okulawulwa yi-InsP₈ kunokusasazeka kwizityalo ezisandul’ ukuzalwa, oku kufunyaniswayo kunokuvula indlela yokuphuhliswa kwezityalo ezivelisa isivuno esiphezulu zesizukulwana esilandelayo.
Ixesha leposi: Oktobha-31-2025