Lolu cwaningo lubonisa ukuthi i-rhizosphere symbiotic fungus *Kosakonia oryphila* NP19 ehlukaniswe nezimpande zelayisi iyi-biopesticide ethembisayo ekhuthaza ukukhula kwesitshalo futhi ikhuthaza i-biopesticide yokulawula ukuqhuma kwelayisi okubangelwa yi-*Pyricularia oryzae*. Ukuhlolwa kwe-in vitro kwenziwe emaqabunga amasha ezithombo zelayisi le-jasmine zohlobo lwe-Khao Dawk Mali 105 (KDML105). Imiphumela ibonise ukuthi i-NP19 ivimbele ngempumelelo ukuhluma kwe-*Pyricularia oryzae* conidia. Ukutheleleka kwe-*Pyricularia oryzae* kwavinjelwa ngaphansi kwezimo ezintathu ezahlukene zokwelapha: okokuqala, ilayisi lafakwa ikoloni nge-NP19 futhi lafakwa i-*Pyricularia oryzae* conidia; okwesibili, ingxube ye-NP19 kanye ne-*Pyricularia oryzae* conidia yafakwa emaqabunga;
Ibhaktheriya ye-rhizosphere *Kosakonia oryziphila* NP1914yahlukaniswa nezimpande zelayisi (*Oryza sativa* L. cv. RD6). *I-Kosakonia oryziphila* NP19 inezakhiwo ezikhuthaza ukukhula kwezitshalo, okuhlanganisa nokufakwa kwe-nitrogen, ukukhiqizwa kwe-indoleacetic acid (IAA), kanye nokuncibilikiswa kwe-phosphate. Ngokuthakazelisayo, *I-Kosakonia oryziphila* NP19 ikhiqiza i-chitinase14.Ukusetshenziswa kwembewu yelayisi i-*Kosakonia oryziphila* NP19 kumbewu yelayisi i-KDML105 kuthuthukise ukusinda kwelayisi ngemva kokutheleleka nge-rice blast. Inhloso yalolu cwaningo (i) ukucacisa indlela yokuvimbela i-*Kosakonia oryziphila* NP19 ngokumelene ne-rice blast kanye (ii) nokuphenya umphumela we-*Kosakonia oryziphila* NP19 ekulawuleni i-rice blast.
Izakhamzimba zidlala indima ebalulekile ekukhuleni nasekuthuthukisweni kwezitshalo, zisebenza njengezinto ezilawula izifo ezahlukahlukene zamagciwane. Ukudla okunezamaminerali kwesitshalo kunquma ukumelana kwaso nezifo, izici zesimo noma zezicubu, kanye nokuba khona kwaso, noma ikhono lokusinda ezifweni ezibangelwa amagciwane. I-phosphorus inganciphisa ukukhula futhi inciphise ubunzima bokuqhuma kwerayisi ngokwandisa ukwakheka kwamakhemikhali e-phenolic. I-Potassium ngokuvamile inciphisa ukwanda kwezifo eziningi zerayisi, njengokuqhuma kwerayisi, indawo yamaqabunga ebhaktheriya, indawo yesikhumba samaqabunga, ukubola kwesiqu, kanye nendawo yamaqabunga. Ucwaningo olwenziwe nguPerrenoud lukhombisile ukuthi umanyolo one-potassium ephezulu unganciphisa futhi ukwanda kwezifo zefungal zerayisi futhi wandise isivuno. Izifundo eziningi zikhombisile ukuthi umanyolo we-sulfur ungathuthukisa ukumelana kwezitshalo ezifweni ezibangelwa amagciwane ezibangelwa amagciwane.27I-magnesium eningi (ingxenye ye-chlorophyll) ingaholela ekuqhumeni kwelayisi.21I-Zinc ingabulala ngqo amagciwane, ngaleyo ndlela inciphise ubukhali besifo.22Ukuhlolwa kwasensimini kubonise ukuthi nakuba amazinga e-phosphorus, i-potassium, i-sulfur, ne-zinc enhlabathini yasensimini ayephezulu kunasekuhlolweni kwebhodwe, ukuqhuma kwelayisi kusasakazeka emaqabungeni elayisi. Izakhamzimba zomhlabathi zingase zingabi wusizo kakhulu ekulawuleni ukuqhuma kwelayisi, njengoba umswakama kanye nokushisa okuhlobene kungafaneleki ekuhlaselweni okunamandla kwezifo.
Ezivivinyweni zasensimini, i-Stenotrophomonas maltophilia, i-P. dispersa, i-Xanthomonas sacchari, i-Burkholderia multivorans, i-Burkholderia diffusa, i-Burkholderia vietnamiensis kanye ne-C. gleum kutholakale kuzo zonke izindlela zokwelapha. I-Stenotrophomonas maltophilia ihlukaniswe ne-rhizosphere kakolweni, i-oats, ikhukhamba, ummbila, kanye namazambane futhi ibonise ukulawula kwe-bio.umsebenzingokumelene ne-Colletotrichum nymphaeae.28 Ngaphezu kwalokho, i-P. dispersa ibikwe ukuthi isebenza kahle ngokumelene nomnyamaukubolaubhatata.29 Ngaphezu kwalokho, uhlobo lwe-R1 lwe-Xanthomonas sacchari lubonise ukusebenza okuphambene nokubola kwerayisi okubangelwa yi-Burkholderiai-glumae.30I-Burkholderia oryzae NP19 ingasungula ubudlelwano bokubambisana nezicubu zelayisi ngesikhathi sokuhluma futhi ibe yi-fungus ehlala njalo yezinhlobo zelayisi ezithile. Ngenkathi amanye amabhaktheriya enhlabathi engahlala elayisini ngemva kokufakelwa, i-blast fungus NP19, uma isihlanganisiwe, ithonya izici eziningi endleleni yokuzivikela yelayisi kulesi sifo. I-NP19 ayigcini nje ngokucindezela ukukhula kwe-P. oryzae ngaphezu kuka-50% (bheka Ithebula Elingeziwe S1 esihlokweni esiku-inthanethi), kodwa futhi inciphisa inani lezilonda zokuqhuma emaqabunga futhi ikhuphule isivuno serayisi elifakwe noma elihlanganisiwe ne-NP19 (RBf, RFf-B, kanye ne-RBFf-B) ezivivinyweni zasensimini (Isithombe S3).
I-fungus i-Pyricularia oryzae, ebangela ukuqhuma kwezitshalo, iyi-fungus ehlala isikhathi eside edinga izakhamzimba ezivela esitshalweni esiphethe ngesikhathi sokutheleleka. Izitshalo zikhiqiza izinhlobo ze-oxygen ezisebenzayo (i-ROS) ukuze zivimbele ukutheleleka kwe-fungus; noma kunjalo, i-Pyricularia oryzae isebenzisa amasu ahlukahlukene ukulwa ne-ROS ekhiqizwa ngumnikazi.31Ama-peroxidases abonakala edlala indima ekumelaneni namagciwane, okuhlanganisa ukuxhumanisa amaprotheni odonga lweseli, ukuqina kwezindonga ze-xylem, ukukhiqizwa kwe-ROS, kanye nokunciphisa i-hydrogen peroxide.32Ama-enzyme e-antioxidant angasebenza njengohlelo oluthile lokususa i-ROS. Ngezakhiwo zawo ze-antioxidant, i-superoxide dismutase (SOD) kanye ne-peroxidase (POD) zisiza ekuqaliseni izimpendulo zokuzivikela, kanti i-SOD isebenza njengomugqa wokuqala wokuzivikela.33Elayisini, umsebenzi we-peroxidase yezitshalo ubangelwa ngemva kokutheleleka ngamagciwane ezitshalo njenge-*Pyricularia oryzae* kanye ne-*Xanthomonas oryzae pv. Oryzae*.32Kulesi sifundo, umsebenzi we-peroxidase wanda elayisini eliqoqwe futhi/noma elifakwe i-*Magnaporthe oryzae* NP19; noma kunjalo, i-*Magnaporthe oryzae* ayizange ithinte umsebenzi we-peroxidase. I-Superoxide dismutase (SOD), njenge-H₂O₂ synthase, ikhuthaza ukwehla kwe-O₂⁻ ku-H₂O₂. I-SOD idlala indima ebalulekile ekumelaneni nezitshalo ezingcindezini ezahlukahlukene ngokulinganisa ukuhlushwa kwe-H₂O₂ ngaphakathi kwesitshalo, ngaleyo ndlela ithuthukise ukubekezelela izitshalo ezingcindezini ezahlukahlukene³⁴. Kulesi sifundo, ekuhlolweni kwembiza, ezinsukwini ezingama-30 ngemuva kokugonywa kwe-*Magnaporthe oryzae* (30 DAT), imisebenzi ye-SOD emaqenjini e-RF kanye ne-RBF yayiphezulu ngo-121.9% kanye no-104.5% kunaleyo eseqenjini le-R, ngokulandelana, okubonisa impendulo ye-SOD ekuthelelekeni kwe-*Magnaporthe oryzae*. Kokubili ukuhlolwa kwembiza kanye nokwensimu, imisebenzi ye-SOD elayisini elifakwe i-*Magnaporthe oryzae* NP19 yayiphezulu ngo-67.7% kanye no-28.8% kunaleyo elayisini elingafakwanga i-incopy ezinsukwini ezingu-30 ngemuva kokugonywa, ngokulandelana. Izimpendulo ze-biochemical zezitshalo zithinteka yindawo ezungezile, umthombo wokucindezeleka, kanye nohlobo lwesitshalo³⁵. Imisebenzi ye-enzyme ye-antioxidant yezitshalo ithinteka ngqo yizici zemvelo, ezithinta imisebenzi ye-enzyme ye-antioxidant yezitshalo ngokushintsha umphakathi we-microbial yezitshalo.
Isikhunta se-rice blast disease (Kosakonia oryziphila NP19, inombolo yokungena ye-NCBI PP861312) esisetshenziswe kulolu cwaningo sasiwuhlobo lwe-strain.13ihlukaniswe nezimpande zerayisi i-RD6 eSifundazweni saseNakhon Phanom, eThailand (16° 59′ 42.9″ N 104° 22′ 17.9″ E). Lolu hlobo lwatshalwa emhluzi wezakhamzimba (NB) ku-30°C kanye no-150 rpm amahora angu-18. Ukuze kubalwe ukuhlushwa kwamagciwane, kwalinganiswa ukumuncwa kokuhlushwa kwamagciwane ku-600 nm. Ukuhlushwa kokuhlushwa kwamagciwane kwalungiswa kwaba10⁶I-CFU/mL ngamanzi ahlanzekile angenawo i-ion (i-dH₂O). I-Rice blast fungus (Pyricularia oryzae) yafakwa i-spot-inculated ku-potato dextrose agar (PDA) futhi yafakwa ku-25°C izinsuku eziyi-7. I-fungal mycelium yadluliselwa ku-rice bran agar medium (2% (w/v) rice bran, 0.5% (w/v) sucrose, kanye ne-2% (w/v) agar encibilikisiwe emanzini acwengekile, i-pH 7) futhi yafakwa ku-25°C izinsuku eziyi-7. Iqabunga elihlanziwe le-cultivar yerayisi esengozini (KDML105) labekwa ku-mycelium ukuze kubangele i-conidia futhi lafakwa ku-25°C izinsuku eziyi-5 ngaphansi kwe-UV ehlanganisiwe kanye nokukhanya okumhlophe. Ama-Conidia aqoqwe ngokusula ngobumnene i-mycelium kanye nobuso beqabunga elithelelekile nge-10 ml yesisombululo se-0.025% (v/v) Tween 20 esihlanziwe. Isixazululo se-fungal sahlungwa ngezingqimba eziyisishiyagalombili ze-cheesecloth ukuze kususwe i-mycelium, i-agar, kanye namaqabunga elayisi. Ukuhlushwa kwe-conidia ekumisweni kulungiswe kwaba yi-5 × 10⁵ conidia/ml ukuze kuhlaziywe kabanzi.
Ama-culture amasha amaseli e-Kosakonia oryziphila NP19 alungiswa ngokuwasika endaweni ephakathi ye-NB ku-37 °C amahora angama-24. Ngemva kokufaka i-centrifugation (3047 × g, imizuzu eyi-10), i-pellet yeseli yaqoqwa, yagezwa kabili nge-10 mM phosphate-buffered saline (PBS, pH 7.2), yaphinde yaxhonywa ku-buffer efanayo. Ubuningi be-optical bokumiswa kweseli balinganiswa ku-600 nm, bathola inani elicishe libe ngu-1.0 (elilingana no-1.0 × 10⁷ CFU/μl elinqunywe ngokufaka amapuleti e-nutrient agar). I-Conidia ye-P. oryzae yatholakala ngokuwamisa kusisombululo se-PBS bese ibalwa kusetshenziswa i-hemocytometer. Ukumiswa kwe-*K. oryziphila* NP19 kanye ne-*P. Kulezi zivivinyo ze-leaf smear, i-K. oryphila* conidia yalungiswa emaqabungeni elayisi amasha ngokugxila okungu-1.0 × 10⁷ CFU/μL kanye no-5.0 × 10² conidia/μL, ngokulandelana. Indlela yokulungiselela isampula yelayisi yayinje: amaqabunga amade angu-5 cm avela ezithonjeni zerayisi anqunywa abekwa ezitsheni zePetri ezimbozwe ngephepha elimanzi elimunca amanzi. Kwasungulwa amaqembu amahlanu okwelapha: (i) R: amaqabunga elayisi angenawo umuthi wamagciwane njengendlela yokulawula, angezwe ngo-0.025% (v/v) Isixazululo esiphakathi kuka-20; (ii) RB + F: ilayisi elifakwe umuthi we-K. oryphila NP19, elingezwe ngo-2 μL wokumiswa kwe-conidia kwesikhunta esibangela ukuqhuma kwelayisi; (iii) R + BF: Ilayisi eqenjini R elingezwe ngo-4 μl wengxube ye-blast fungal conidia suspension kanye ne-K. oryphila NP19 (isilinganiso sevolumu 1:1); (iv) R + F: Ilayisi eqenjini R lifakwe ama-2 μl okumiswa kwe-blast fungal conidia; (v) RF + B: Ilayisi eqenjini R lifakwe ama-2 μl okumiswa kwe-blast fungal conidia lafakwa e-incubation amahora angama-30, kwabe sekufakwa ama-2 μl e-K. oryziphila NP19 endaweni efanayo. Zonke izitsha ze-Petri zafakwa e-incubation kuma-25°C ebumnyameni amahora angama-30 zabe sezibekwa ngaphansi kokukhanya okuqhubekayo. Iqembu ngalinye lakhiwa kathathu. Ngemva kwamahora angama-72 okukhula, izicubu zezitshalo zabonwa futhi zahlaziywa nge-scanning electron microscopy (SEM). Kafushane, izicubu zezitshalo zaqiniswa ku-phosphate buffer equkethe i-2.5% (v/v) glutaraldehyde futhi zacwiliswa ngochungechunge lwezixazululo ze-ethanol. Ngemva kokomiswa kwe-critical-point nge-carbon dioxide, amasampula agcotshwa ngegolide futhi ekugcineni ahlolwa kusetshenziswa i-scanning electron microscope.15
Isikhathi sokuthunyelwe: Disemba 15-2025