Olu phononongo lubonisa ukuba i-rhizosphere symbiotic fungus *Kosakonia oryphila* NP19 ekhutshwe kwiingcambu zerayisi yi-biopesticide ethembisayo ekhuthaza ukukhula kwezityalo kunye ne-biopesticide yokulawula ukuqhuma kwerayisi okubangelwa yi-*Pyricularia oryzae*. Uvavanyo lwe-in vitro lwenziwe kumagqabi amatsha ezityalo zerayisi ze-jasmine zohlobo lwe-Khao Dawk Mali 105 (KDML105). Iziphumo zibonise ukuba i-NP19 ithintele ngempumelelo ukuhluma kwe-*Pyricularia oryzae* conidia. Usulelo lwe-*Pyricularia oryzae* lwathintelwa phantsi kweemeko ezintathu ezahlukeneyo zonyango: okokuqala, irayisi yafakwa kwi-NP19 yaza yafakwa kwi-*Pyricularia oryzae* conidia; okwesibini, umxube we-NP19 kunye ne-*Pyricularia oryzae* conidia wafakwa kumagqabi;
Ibhaktheriya yerhizosphere *Kosakonia oryziphila* NP1914yahlulwa kwiingcambu zerayisi (*Oryza sativa* L. cv. RD6). *I-Kosakonia oryziphila* NP19 ineempawu zokukhuthaza ukukhula kwezityalo, kubandakanya ukulungiswa kwe-nitrogen, imveliso ye-indoleacetic acid (IAA), kunye nokunyibilika kwe-phosphate. Okunomdla kukuba, *I-Kosakonia oryziphila* NP19 ivelisa i-chitinase14.Ukusetyenziswa kwembewu yerayisi ye-*Kosakonia oryziphila* NP19 kwimbewu yerayisi ye-KDML105 kuphucule ukusinda kwerayisi emva kokosuleleka yirayisi. Injongo yolu phononongo kuku (i) cacisa indlela yokuthintela i-*Kosakonia oryziphila* NP19 ngokuchasene nerayisi kunye (ii) phando ngesiphumo se-*Kosakonia oryziphila* NP19 ekulawuleni irayisi.
Izakhamzimba zidlala indima ebalulekileyo ekukhuleni nasekuphuhlisweni kwezityalo, zisebenza njengezinto ezilawula izifo ezahlukeneyo zeentsholongwane. Isondlo seeminerali sesityalo simisela ukumelana kwaso nezifo, iimpawu zesimo okanye zezicubu, kunye nokuba yingozi kangakanani, okanye amandla okusinda kwiintsholongwane. I-Phosphorus inokucothisa uphuhliso kwaye inciphise ubunzima bokuqhuma kwerayisi ngokwandisa ukwenziwa kwee-phenolic compounds. I-Potassium ngokubanzi inciphisa ukwanda kwezifo ezininzi zerayisi, ezifana nokuqhuma kwerayisi, indawo yebhaktiriya, indawo yesheya legqabi, ukubola kwesiqu, kunye nendawo yegqabi. Uphononongo olwenziwe nguPerrenoud lubonise ukuba izichumisi ezine-potassium eninzi zinokunciphisa ukwanda kwezifo zefungus zerayisi kwaye zonyuse isivuno. Izifundo ezininzi zibonise ukuba izichumisi zesulfure zinokuphucula ukumelana kwezityalo nezifo zefungus.27I-magnesium egqithisileyo (inxalenye ye-chlorophyll) inokubangela ukudumba kwerayisi.21I-Zinc inokubulala ngokuthe ngqo iintsholongwane, ngaloo ndlela inciphisa ubukhali besifo.22Uvavanyo lwasemasimini lubonise ukuba nangona ubuninzi be-phosphorus, i-potassium, i-sulfur, kunye ne-zinc kumhlaba wasemasimini buphezulu kunakwilingo lembiza, ukuqhuma kwerayisi kusasasazeka kumagqabi erayisi. Izondlo zomhlaba zisenokungasebenzi kakuhle ekulawuleni ukuqhuma kwerayisi, njengoko umswakama kunye nobushushu obufanelekileyo kungafaneleki kwintsholongwane enamandla.
Kwizilingo zasentsimini, iStenotrophomonas maltophilia, iP. dispersa, iXanthomonas sacchari, iBurkholderia multivorans, iBurkholderia diffusa, iBurkholderia vietnamiensis kunye neC. gleum zifunyenwe kuzo zonke iindlela zonyango. IStenotrophomonas maltophilia ihlulwe kwi-rhizosphere yengqolowa, i-oats, ikhukhamba, umbona, kunye neetapile kwaye ibonakalise ulawulo lwebhayoloji.umsebenzinxamnye neColletotrichum nymphaeae.28 Ngaphezu koko, kuye kwaxelwa ukuba i-P. dispersa isebenza ngokuchasene nomnyamaukubolaIbhatata emnandi.29 Ngaphezu koko, uhlobo lwe-R1 lweXanthomonas sacchari lubonakalise ukusebenza ngokuchasene nerayisi eqhumayo kunye nokubola kwe-panicle okubangelwa yiBurkholderiai-glumae.30I-Burkholderia oryzae NP19 inokwenza ubudlelwane bokubambisana nezicubu zerayisi ngexesha lokuhluma kwaye ibe yi-fungus ehlala ihleli kwezinye iintlobo zerayisi. Ngelixa ezinye iibhaktheriya zomhlaba zinokuhlala irayisi emva kokufakelwa, i-blast fungus NP19, xa sele ihleli, inefuthe kwizinto ezininzi kwindlela yokukhusela irayisi kwesi sifo. I-NP19 ayigcini nje ngokuthintela ukukhula kwe-P. oryzae ngaphezulu kwe-50% (jonga iTheyibhile eyoNgezelelweyo S1 kwisihlomelo se-intanethi), kodwa ikwanciphisa inani lezilonda zokuqhuma kumagqabi kwaye yonyusa isivuno serayisi efakwe okanye efakwe i-NP19 (RBf, RFf-B, kunye ne-RBFf-B) kuvavanyo lwasemasimini (Umfanekiso S3).
I-fungus i-Pyricularia oryzae, ebangela ukuqhuma kwezityalo, yi-fungus ehlala ikhula edinga izondlo kwisityalo esisithwalayo ngexesha losulelo. Izityalo zivelisa iintlobo ze-oxygen ezisabelayo (i-ROS) ukuze zithintele usulelo lwe-fungus; nangona kunjalo, i-Pyricularia oryzae isebenzisa amaqhinga ahlukeneyo ukulwa ne-ROS eveliswa ngumninimzi.31Kubonakala ngathi ii-peroxidases zidlala indima ekuchaseni iintsholongwane, kubandakanya ukudibanisa iiproteni zodonga lweseli, ukuqina kweendonga ze-xylem, ukuveliswa kweROS, kunye nokungaguquguquki kwe-hydrogen peroxide.32Iienzymes ze-Antioxidant zingasebenza njengenkqubo ethile yokususa ii-ROS. Ngenxa yeempawu zazo ze-antioxidant, i-superoxide dismutase (SOD) kunye ne-peroxidase (POD) zinceda ekuqaliseni iimpendulo zokuzikhusela, i-SOD isebenza njengomgca wokuqala wokuzikhusela.33Kwirayisi, umsebenzi we-peroxidase yezityalo ubangelwa emva kokosulelwa zizifo zezityalo ezifana ne-*Pyricularia oryzae* kunye ne-*Xanthomonas oryzae pv. Oryzae*.32Kolu phononongo, umsebenzi we-peroxidase wanda kwirayisi ebekwe kwaye/okanye efakwe i-*Magnaporthe oryzae* NP19; nangona kunjalo, *Magnaporthe oryzae* ayizange ichaphazele umsebenzi we-peroxidase. I-Superoxide dismutase (SOD), njenge-H₂O₂ synthase, ikhuthaza ukunciphisa i-O₂⁻ ukuya kwi-H₂O₂. I-SOD idlala indima ebalulekileyo ekuchaseni izityalo kwiingcinezelo ezahlukeneyo ngokulinganisela uxinzelelo lwe-H₂O₂ ngaphakathi kwesityalo, ngaloo ndlela iphucula ukunyamezela izityalo kwiingcinezelo ezahlukeneyo³⁴. Kolu phononongo, kuvavanyo lwembiza, kwiintsuku ezingama-30 emva kwe-*Magnaporthe oryzae* inoculation (30 DAT), imisebenzi ye-SOD kumaqela e-RF kunye ne-RBF yayiphezulu nge-121.9% kunye ne-104.5% kunaleyo ikwiqela le-R, ngokwahlukeneyo, nto leyo ebonisa impendulo ye-SOD kwi-*Magnaporthe oryzae* usulelo. Kuzo zombini iimvavanyo zembiza nezentsimi, imisebenzi ye-SOD kwirayisi efakwe i-*Magnaporthe oryzae* NP19 yayiphezulu ngama-67.7% kunye nama-28.8% kunaleyo ikwirayisi engafakwanga i-incopy kwiintsuku ezingama-30 emva kokuyifaka, ngokulandelelana. Iimpendulo zebhayoloji yezityalo zichaphazeleka yimeko-bume, umthombo woxinzelelo, kunye nohlobo lwesityalo³⁵. Imisebenzi ye-enzyme ye-antioxidant yezityalo ichaphazeleka ngokuthe ngqo zizinto ezingqongileyo, ezithi ke zona zichaphazele imisebenzi ye-enzyme ye-antioxidant yezityalo ngokutshintsha uluntu lwe-microbial yezityalo.
Ifungus yesifo se-rice blast (Kosakonia oryziphila NP19, inombolo yokwamkelwa kwe-NCBI PP861312) esetyenziswe kolu phononongo yayiluhlobo lwe-strain.13yahlulwe kwiingcambu zerayisi e-RD6 kwiPhondo laseNakhon Phanom, eThailand (16° 59′ 42.9″ N 104° 22′ 17.9″ E). Olu hlobo lwatyalwa kumhluzi wezondlo (NB) kwi-30°C kunye ne-150 rpm kangangeeyure ezili-18. Ukuze kubalwe uxinano lwebhaktiriya, kwalinganiswa ukufunxwa komxube webhaktiriya kwi-600 nm. Uxinano lomxube webhaktiriya lwalungiswa ukuze10⁶I-CFU/mL enamanzi angenazo ii-ion (dH₂O). I-Rice blast fungus (Pyricularia oryzae) yafakwa kwi-potato dextrose agar (PDA) yaza yafakwa kwi-incubator kwi-25°C kangangeentsuku ezisi-7. I-fungus mycelium yadluliselwa kwi-rice bran agar medium (2% (w/v) rice bran, 0.5% (w/v) sucrose, kunye ne-2% (w/v) agar enyibilikiswe emanzini acocekileyo, i-pH 7) yaza yafakwa kwi-incubator kwi-25°C kangangeentsuku ezisi-7. Igqabi elicociweyo le-rayisi enokuchaphazeleka (KDML105) labekwa kwi-mycelium ukuze libangele i-conidia kwaye lafakwa kwi-incubator kwi-25°C kangangeentsuku ezi-5 phantsi kokukhanya okudibeneyo kwe-UV kunye nokukhanya okumhlophe. I-Conidia yaqokelelwa ngokusula ngobunono i-mycelium kunye nomphezulu wegqabi elinentsholongwane nge-10 ml yesisombululo se-0.025% (v/v) esicociweyo phakathi kwama-20. Isisombululo se-fungus sahluzwa ngeengqimba ezisibhozo ze-cheesecloth ukususa i-mycelium, i-agar, kunye namagqabi erayisi. Uxinzelelo lwe-conidia kwi-suspension lulungiswe kwi-5 × 10⁵ conidia/ml ukuze kuhlalutywe ngakumbi.
Iinkcubeko ezintsha zeeseli zeKosakonia oryziphila NP19 zalungiswa ngokuzisika kwindawo ephakathi yeNB kwi-37 °C kangangeeyure ezingama-24. Emva kokucocwa (3047 × g, imizuzu eli-10), i-pellet yeseli yaqokelelwa, yahlanjwa kabini nge-10 mM phosphate-buffered saline (PBS, pH 7.2), yaza yaphinda yaxhonywa kwi-buffer efanayo. Ubuninzi be-optical bokumiswa kweseli bulinganiswe kwi-600 nm, kwafunyanwa ixabiso elimalunga ne-1.0 (elilingana ne-1.0 × 10⁷ CFU/μl elimiselwe ngokubeka iiplate ze-nutrient agar). I-Conidia ye-P. oryzae yafunyanwa ngokuzisika kwisisombululo se-PBS kwaye yazibala kusetyenziswa i-hemocytometer. Ukuxhonywa kwe-*K. oryziphila* NP19 kunye ne-*P. Kwizilingo ze-leaf smear, i-K. oryphila* conidia yalungiswa kumagqabi erayisi amatsha kumanqanaba e-1.0 × 10⁷ CFU/μL kunye ne-5.0 × 10² conidia/μL, ngokulandelelana. Indlela yokulungiselela isampuli yerayisi yayilandelayo: Amagqabi amade angama-5 cm avela kwizithole zerayisi anqunyulwa aze abekwe kwizitya zePetri ezigqunywe ngephepha elifunxayo elimanzi. Amaqela amahlanu onyango asekwa: (i) R: amagqabi erayisi angenalo ugonyo lwebhaktiriya njengolawulo, ancediswa yi-0.025% (v/v) Isisombululo esiphakathi kwama-20; (ii) RB + F: irayisi efakwe i-K. oryphila NP19, incediswa yi-2 μL yokumiswa kwe-conidia yefungus ebangela irayisi; (iii) R + BF: Irayisi kwiqela R incediswa yi-4 μl yomxube we-blast fungal conidia suspension kunye ne-K. oryphila NP19 (umlinganiselo wevolumu 1:1); (iv) R + F: Irayisi kwiqela R yongezwe yi-2 μl ye-blast fungal conidia suspension; (v) RF + B: Irayisi kwiqela R yongezwe yi-2 μl ye-blast fungal conidia suspension yafakwa kwi-incubation iiyure ezingama-30, emva koko kongezwa i-2 μl ye-K. oryphila NP19 kwindawo enye. Zonke izitya zePetri zafakwa kwi-incubation kwi-25°C ebumnyameni iiyure ezingama-30 zaza zabekwa phantsi kokukhanya okuqhubekayo. Iqela ngalinye lenziwa kathathu. Emva kweeyure ezingama-72 zokukhula, izicubu zezityalo zajongwa kwaye zahlalutywa nge-scanning electron microscopy (SEM). Ngamafutshane, izicubu zezityalo zafakwa kwi-phosphate buffer equlethe i-2.5% (v/v) glutaraldehyde kwaye zacinywa ngothotho lwezisombululo ze-ethanol. Emva kokomiswa kwindawo ebalulekileyo nge-carbon dioxide, iisampulu zagqunywa ngegolide kwaye ekugqibeleni zahlolwa kusetyenziswa i-scanning electron microscope.15
Ixesha leposi: Disemba-15-2025