Kafukufukuyu akuwonetsa kuti bowa wa rhizosphere symbiotic *Kosakonia oryphila* NP19 wochotsedwa ku mizu ya mpunga ndi mankhwala ophera tizilombo toyambitsa matenda omwe amalimbikitsa kukula kwa zomera kuti athetse kuphulika kwa mpunga komwe kumachitika chifukwa cha *Pyricularia oryzae*. Kuyesera kwa in vitro kunachitika pa masamba atsopano a mbande za mpunga wa jasmine za mtundu wa Khao Dawk Mali 105 (KDML105). Zotsatira zake zasonyeza kuti NP19 inaletsa bwino kumera kwa *Pyricularia oryzae* conidia. Matenda a *Pyricularia oryzae* analetsedwa pansi pa njira zitatu zosiyana zochizira: choyamba, mpunga unalowetsedwa ndi NP19 ndikuyikidwa katemera ndi *Pyricularia oryzae* conidia; chachiwiri, chisakanizo cha NP19 ndi *Pyricularia oryzae* conidia chinayikidwa pamasamba;
Bacterium ya rhizosphere *Kosakonia oryziphila* NP1914idachotsedwa ku mizu ya mpunga (*Oryza sativa* L. cv. RD6). *Kosakonia oryphila* NP19 ili ndi mphamvu zokulitsa kukula kwa zomera, kuphatikizapo kukhazikika kwa nayitrogeni, kupanga indoleacetic acid (IAA), ndi kusungunuka kwa phosphate. Chosangalatsa n'chakuti, *Kosakonia oryphila* NP19 imapanga chitinase.14.Kugwiritsa ntchito *Kosakonia oryziphila* NP19 ku mbewu za mpunga za KDML105 kunathandiza kuti mpunga upulumuke pambuyo poti wagwidwa ndi kachilombo koyambitsa mpunga. Cholinga cha kafukufukuyu ndi (i) kufotokoza momwe *Kosakonia oryziphila* NP19 imalepheretsera mpunga kuphulika ndi (ii) kufufuza momwe *Kosakonia oryziphila* NP19 imakhudzira mpunga kuphulika.
Zakudya zimathandiza kwambiri pakukula ndi chitukuko cha zomera, zomwe zimagwira ntchito ngati zinthu zomwe zimalamulira matenda osiyanasiyana a tizilombo toyambitsa matenda. Zakudya za mchere za chomera zimatsimikizira kukana kwake matenda, mawonekedwe ake kapena minofu, komanso kuopsa kwake, kapena kuthekera kwake kupulumuka motsutsana ndi tizilombo toyambitsa matenda. Phosphorus imatha kuchepetsa kukula ndikuchepetsa kuopsa kwa kuphulika kwa mpunga powonjezera kupanga kwa mankhwala a phenolic. Potaziyamu nthawi zambiri imachepetsa kuchuluka kwa matenda ambiri a mpunga, monga kuphulika kwa mpunga, banga la tsamba la bakiteriya, banga la tsamba, kubola kwa tsinde, ndi banga la tsamba. Kafukufuku wa Perrenoud adawonetsa kuti feteleza wokhala ndi potaziyamu wambiri amathanso kuchepetsa kuchuluka kwa matenda a bowa a mpunga ndikuwonjezera zokolola. Kafukufuku wambiri wasonyeza kuti feteleza wa sulfure amatha kupititsa patsogolo kukana kwa mbewu ku matenda a bowa.27Magnesium wochuluka (womwe ndi gawo la chlorophyll) ungayambitse kuphulika kwa mpunga.21Zinc imatha kupha tizilombo toyambitsa matenda mwachindunji, motero imachepetsa kuopsa kwa matenda.22Mayeso akumunda adawonetsa kuti ngakhale kuchuluka kwa phosphorous, potaziyamu, sulfure, ndi zinc m'nthaka yamunda kunali kokwera kuposa momwe zidachitikira mumphika, kuphulika kwa mpunga kumafalikirabe kudzera m'masamba a mpunga. Zakudya za m'nthaka sizingakhale zothandiza kwambiri poletsa kuphulika kwa mpunga, chifukwa chinyezi ndi kutentha sizili bwino pakukula kwa tizilombo toyambitsa matenda.
Mu mayeso akumunda, Stenotrophomonas maltophilia, P. dispersa, Xanthomonas sacchari, Burkholderia multivorans, Burkholderia diffusa, Burkholderia vietnamiensis ndi C. gleum adapezeka mu mankhwala onse. Stenotrophomonas maltophilia yapezeka kuchokera ku rhizosphere ya tirigu, oats, nkhaka, chimanga, ndi mbatata ndipo yawonetsa kulamulira kwa bio.ntchitomotsutsana ndi Colletotrichum nymphaeae.28 Kuphatikiza apo, P. dispersa yanenedwa kuti imagwira ntchito motsutsana ndi wakudakuvunda kwaMbatata yokoma.29 Komanso, mtundu wa R1 wa Xanthomonas sacchari wasonyeza kuti umagwira ntchito motsutsana ndi mpunga wophulika ndi kuwola kwa panicle komwe kumachitika chifukwa cha Burkholderia.glumae.30Burkholderia oryzae NP19 imatha kukhazikitsa ubale wogwirizana ndi minofu ya mpunga ikamera ndipo imakhala bowa wogwirizana ndi mitundu ina ya mpunga. Ngakhale mabakiteriya ena a m'nthaka amatha kukhazikika mu mpunga atangoikidwa m'malo ena, bowa wophulika NP19, akangolowa m'malo ena, umakhudza zinthu zingapo pa njira yodzitetezera ku matendawa. NP19 sikuti imangoletsa kukula kwa P. oryzae ndi oposa 50% (onani Supplementary Table S1 mu appendix ya pa intaneti), komanso imachepetsa kuchuluka kwa zilonda zophulika pamasamba ndikuwonjezera zokolola za mpunga wothiridwa kapena wolowetsedwa ndi NP19 (RBf, RFf-B, ndi RBFf-B) m'mayesero akumunda (Chithunzi S3).
Bowa wa Pyricularia oryzae, womwe umayambitsa kuphulika kwa zomera, ndi bowa woopsa kwambiri womwe umafunikira michere kuchokera ku chomera chomwe chimalandira panthawi ya matenda. Zomera zimapanga mitundu ya okosijeni yogwira ntchito (ROS) kuti zichepetse matenda a bowa; komabe, Pyricularia oryzae imagwiritsa ntchito njira zosiyanasiyana kuti ithane ndi ROS yomwe imapangidwa ndi chomeracho.31Ma peroxidases akuwoneka kuti ali ndi gawo lofunikira pakulimbana ndi tizilombo toyambitsa matenda, kuphatikizapo kulumikiza mapuloteni a makoma a maselo, kukhuthala kwa makoma a xylem, kupanga ROS, komanso kuletsa hydrogen peroxide.32Ma enzyme oletsa kuwononga ma oxidant atha kukhala njira yeniyeni yochotsera ma ROS. Kudzera mu mphamvu zawo zoletsa kuwononga ma antioxidants, superoxide dismutase (SOD) ndi peroxidase (POD) zimathandiza kuyambitsa mayankho a chitetezo, ndipo SOD imakhala ngati mzere woyamba wa chitetezo.33Mu mpunga, mphamvu ya peroxidase ya zomera imayamba chifukwa cha matenda a zomera monga *Pyricularia oryzae* ndi *Xanthomonas oryzae pv. Oryzae*.32Mu kafukufukuyu, mphamvu ya peroxidase inawonjezeka mu mpunga womwe unalowetsedwa ndi/kapena womwe unalowetsedwa ndi *Magnaporthe oryzae* NP19; komabe, *Magnaporthe oryzae* sinakhudze ntchito ya peroxidase. Superoxide dismutase (SOD), monga H₂O₂ synthase, imalimbikitsa kuchepetsa kwa O₂⁻ kukhala H₂O₂. SOD imagwira ntchito yofunika kwambiri pakukana kwa zomera ku zovuta zosiyanasiyana poyesa kuchuluka kwa H₂O₂ mkati mwa chomera, motero imakulitsa kupirira kwa zomera ku zovuta zosiyanasiyana³⁴. Mu kafukufukuyu, mu kuyesa kwa mphika, masiku 30 pambuyo pa *Magnaporthe oryzae* inoculation (30 DAT), ntchito za SOD m'magulu a RF ndi RBF zinali 121.9% ndi 104.5% kuposa zomwe zili m'gulu la R, motsatana, zomwe zikusonyeza kuti SOD yayankha ku matenda a *Magnaporthe oryzae*. Mu zoyeserera zonse ziwiri za mphika ndi kumunda, zochita za SOD mu mpunga wothira mankhwala a *Magnaporthe oryzae* NP19 zinali zokwera ndi 67.7% ndi 28.8% kuposa zomwe zili mu mpunga wosathira mankhwala patatha masiku 30 mutathira mankhwala, motsatana. Mayankho a biochemical a zomera amakhudzidwa ndi chilengedwe, gwero la kupsinjika maganizo, ndi mtundu wa zomera³⁵. Zochita za ma enzyme othira mankhwala a zomera zimakhudzidwa mwachindunji ndi zinthu zachilengedwe, zomwe zimakhudza zochita za ma enzyme othira mankhwala a zomera posintha gulu la tizilombo toyambitsa matenda a zomera.
Bowa wa matenda a mpunga (Kosakonia oryziphila NP19, nambala ya NCBI accession PP861312) womwe unagwiritsidwa ntchito mu kafukufukuyu unali wa mtundu wa mpunga.13yochotsedwa ku mizu ya mpunga wa RD6 ku Nakhon Phanom Province, Thailand (16° 59′ 42.9″ N 104° 22′ 17.9″ E). Mtundu uwu unalimidwa mu msuzi wa michere (NB) pa 30°C ndi 150 rpm kwa maola 18. Kuti muwerenge kuchuluka kwa bakiteriya, kuyeza kuyamwa kwa kulowetsedwa kwa bakiteriya pa 600 nm. Kuchuluka kwa kulowetsedwa kwa bakiteriya kunasinthidwa kuti10⁶CFU/mL yokhala ndi madzi osapangidwa ndi ayoni (sterile deionic water)dH₂O). Bowa wa mpunga (Pyricularia oryzae) unayikidwa pa potato dextrose agar (PDA) ndipo unayikidwa pa kutentha kwa 25°C kwa masiku 7. Bowa wa mycelium unasamutsidwira ku rice bran agar medium (2% (w/v) rice bran, 0.5% (w/v) sucrose, ndi 2% (w/v) agar wosungunuka m'madzi opanda ayoni, pH 7) ndipo unayikidwa pa kutentha kwa 25°C kwa masiku 7. Tsamba losawilitsidwa la mtundu wa mpunga wofooka (KDML105) linayikidwa pa mycelium kuti lipange conidia ndipo linaikidwa pa kutentha kwa 25°C kwa masiku 5 pansi pa UV ndi kuwala koyera. Conidia inasonkhanitsidwa popukuta pang'onopang'ono mycelium ndi tsamba lomwe lakhudzidwa ndi kachilomboka ndi 10 ml ya yankho losawilitsidwa la 0.025% (v/v) Tween 20. Yankho la bowa linasefedwa kudzera m'magawo asanu ndi atatu a cheesecloth kuti achotse mycelium, agar, ndi masamba a mpunga. Kuchuluka kwa conidia mu kuyimitsidwa kunasinthidwa kukhala 5 × 10⁵ conidia/ml kuti iwunikidwenso.
Ma cell atsopano a Kosakonia oryziphila NP19 anakonzedwa mwa kuwakulitsa mu NB medium pa 37 °C kwa maola 24. Pambuyo pa centrifugation (3047 × g, mphindi 10), pellet ya cell inasonkhanitsidwa, kutsukidwa kawiri ndi 10 mM phosphate-buffered saline (PBS, pH 7.2), ndikuyiyikanso mu buffer yomweyo. Kuchuluka kwa kuwala kwa cell suspension kunayesedwa pa 600 nm, kupeza mtengo wa pafupifupi 1.0 (wofanana ndi 1.0 × 10⁷ CFU/μl wodziwika ndi kupaka pa mbale za agar za michere). Conidia ya P. oryzae inapezeka mwa kuwayimitsa mu yankho la PBS ndikuwerengera pogwiritsa ntchito hemocytometer. Kuyimitsa kwa *K. oryziphila* NP19 ndi *P. Pa kuyesa kwa masamba, K. oryphila* conidia inakonzedwa pa masamba atsopano a mpunga pamlingo wa 1.0 × 10⁷ CFU/μL ndi 5.0 × 10² conidia/μL, motsatana. Njira yokonzekera chitsanzo cha mpunga inali motere: Masamba a mpunga aatali masentimita 5 adadulidwa ndikuyikidwa mu mbale za Petri zophimbidwa ndi pepala lonyowa loyamwa. Magulu asanu ochizira adakhazikitsidwa: (i) R: masamba a mpunga opanda katemera wa bakiteriya ngati njira yowongolera, yowonjezera ndi 0.025% (v/v) Pakati pa yankho la 20; (ii) RB + F: mpunga wophimbidwa ndi K. oryphila NP19, wowonjezera ndi 2 μL ya conidia suspension ya bowa yomwe imayambitsa kuphulika kwa mpunga; (iii) R + BF: Mpunga mu gulu R wowonjezera ndi 4 μl ya chisakanizo cha kuphulika kwa fungal conidia suspension ndi K. oryphila NP19 (voliyumu chiŵerengero 1:1); (iv) R + F: Mpunga mu gulu R wowonjezeredwa ndi 2 μl ya blast fungal conidia suspension; (v) RF + B: Mpunga mu gulu R wowonjezeredwa ndi 2 μl ya blast fungal conidia suspension unayikidwa mu incubation kwa maola 30, kenako 2 μl ya K. oryphila NP19 inawonjezedwa pamalo omwewo. Zakudya zonse za Petri zinayikidwa mu incubation pa 25°C mumdima kwa maola 30 kenako n’kuyikidwa pansi pa kuwala kosalekeza. Gulu lililonse linapangidwa katatu. Pambuyo pa maola 72 a culture, minofu ya zomera inayang’aniridwa ndi kufufuzidwa pogwiritsa ntchito scanning electron microscopy (SEM). Mwachidule, minofu ya zomera inakhazikika mu phosphate buffer yokhala ndi 2.5% (v/v) glutaraldehyde ndipo inauma kudzera mu njira zingapo za ethanol. Pambuyo pouma kwambiri ndi carbon dioxide, zitsanzozo zinapakidwa golide ndipo pomaliza pake zinafufuzidwa pogwiritsa ntchito scanning electron microscope.15
Nthawi yotumizira: Disembala-15-2025