Cov kws tshawb fawb los ntawm Department of Biochemistry ntawm Indian Institute of Sciences (IISc) tau tshawb pom lub tshuab tshawb nrhiav ntev siv los ntawm cov nroj tsuag hauv av qub xws li bryophytes (xws li mosses thiab liverworts) rautswj cov nroj tsuag loj hlob- ib tug mechanism uas kuj tau khaws cia nyob rau hauv ntau tsis ntev los no evolved flowering nroj tsuag.
Txoj kev tshawb no, luam tawm nyob rau hauv phau ntawv journal Nature Chemical Biology, tsom rau qhov tsis yog-classical kev cai ntawm DELLA protein, tus tswv txoj kev loj hlob regulator uas yuav inhibit cell division nyob rau hauv embryonic nroj tsuag (cov nroj tsuag av).
"DELLA ua zoo li lub pob nrawm, tab sis yog tias lub pob nrawm no tsis tu ncua, cov nroj tsuag txav tsis tau," piav qhia Debabrata Laha, tus kws tshaj lij ntawm biochemistry thiab tus kws sau ntawv ntawm txoj kev tshawb no. Yog li ntawd, qhov degradation ntawm DELLA cov proteins yog qhov tseem ceeb rau kev txhawb nqa kev loj hlob ntawm cov nroj tsuag. Hauv cov paj ntoo, DELLA yog degraded thaum phytohormonegibberellan (GA)khi rau nws cov receptor GID1, tsim GA-GID1-DELLA complex. Tom qab ntawd, DELLA repressor protein khi rau ubiquitin chains thiab degraded los ntawm 26S proteasome.
Interestingly, bryophytes yog thawj cov nroj tsuag rau colonize av, kwv yees li 500 lab xyoo dhau los. Txawm hais tias lawv tsim cov phytohormone gibberellin (GA), lawv tsis muaj GID1 receptor. Qhov no ua rau cov lus nug: kev loj hlob thiab kev loj hlob ntawm cov nroj tsuag hauv av thaum ntxov tau tswj hwm li cas?
Cov kws tshawb fawb tau siv CRISPR-Cas9 qhov system txhawm rau tshem tawm cov noob VIH sib raug, yog li lees paub lub luag haujlwm ntawm VIH. Cov nroj tsuag tsis muaj lub luag haujlwm VIH enzyme pom muaj kev loj hlob hnyav thiab kev loj hlob tsis xws luag thiab morphological txawv txav, xws li tuab thallus, impaired radial loj hlob, thiab tsis muaj calyx. Cov teeb meem no tau raug kho los ntawm kev hloov kho cov genome cog kom tsim tau ib qho kawg (N-terminus) ntawm VIH enzyme. Siv cov txheej txheem chromatography siab heev, pab pawg tshawb fawb tau tshawb pom tias N-terminus muaj kinase domain uas catalyzes cov khoom ntawm InsP₈.
Cov kws tshawb nrhiav pom tias DELLA yog ib lub hom phiaj ntawm tes ntawm VIH kinase. Tsis tas li ntawd, lawv tau pom tias cov phenotype ntawm MpVIH-tsis muaj cov nroj tsuag zoo ib yam li Miscanthus multiforme nroj tsuag nrog nce DELLA qhia.
"Lub sijhawm no, peb xav txiav txim siab seb DELLA kev ruaj ntseg lossis kev ua haujlwm puas tau txhim kho hauv MpVIH-tsis muaj cov nroj tsuag," said Priyanshi Rana, tus kws kho mob hauv Lahey pawg tshawb fawb thiab thawj tus kws sau ntawv. Raws li lawv qhov kev xav, cov kws tshawb fawb pom tias DELLA inhibition ua rau muaj kev loj hlob thiab kev loj hlob tsis xws luag hauv MpVIH mutant nroj tsuag. Cov kev tshawb pom no qhia tias VIH kinase tsis zoo tswj DELLA, yog li txhawb cov nroj tsuag kev loj hlob thiab kev loj hlob.
Cov kws tshawb fawb tau ua ke cov noob caj noob ces, biochemical, thiab biophysical txoj hauv kev los qhia cov txheej txheem uas inositol pyrophosphate tswj DELLA protein qhia hauv cov bryophyte no. Tshwj xeeb tshaj yog, InsP₈, tsim los ntawm MpVIH, khi rau MpDELLA protein, txhawb nws cov polyubiquitination, uas nyob rau hauv lem ua rau degradation ntawm no repressor protein los ntawm lub proteasome.
Kev tshawb fawb ntawm DELLA cov protein ntau hnub rov qab mus rau Green Revolution, thaum cov kws tshawb fawb tsis paub siv nws lub peev xwm los tsim cov qoob loo ib nrab-dwarf ntau yam. Txawm hais tias nws cov txheej txheem ntawm kev txiav txim tsis paub thaum lub sijhawm, cov thev naus laus zis niaj hnub tau ua rau cov kws tshawb fawb siv cov noob hloov kho los tswj cov haujlwm ntawm cov protein no, yog li txhim kho cov qoob loo zoo.
Raha tau hais tias "Nrog cov pej xeem loj hlob thiab txo qis thaj av ua liaj ua teb, nce qoob loo qoob loo tau dhau los ua qhov tseem ceeb," Raha hais. Muab hais tias InsP₈- tswj DELLA degradation tuaj yeem nthuav dav hauv cov nroj tsuag embryonic, qhov kev tshawb pom no tuaj yeem ua rau txoj hauv kev rau kev txhim kho cov qoob loo uas muaj txiaj ntsig tom ntej.
Post lub sij hawm: Oct-31-2025