Abalawuli bokukhula kwezityalo (ii-PGR)yindlela engabizi kakhulu yokuphucula ukhuseleko lwezityalo phantsi kweemeko zoxinzelelo. Olu phononongo luphande amandla abantu ababiniIi-PGR, i-thiourea (TU) kunye ne-arginine (Arg), ukunciphisa uxinzelelo lwetyuwa kwingqolowa. Iziphumo zibonise ukuba i-TU kunye ne-Arg, ingakumbi xa zisetyenziswa kunye, zinokulawula ukukhula kwezityalo phantsi koxinzelelo lwetyuwa. Unyango lwazo lwandise kakhulu imisebenzi yee-enzymes ze-antioxidant ngelixa zinciphisa amanqanaba e-reactive oxygen species (ROS), i-malondialdehyde (MDA), kunye nokuvuza kwe-electrolyte (REL) kwizithole zengqolowa. Ukongeza, ezi ndlela zonyango zinciphise kakhulu uxinano lwe-Na+ kunye ne-Ca2+ kunye nomlinganiselo we-Na+/K+, ngelixa zinyusa kakhulu uxinano lwe-K+, ngaloo ndlela zigcina ibhalansi ye-ion-osmotic. Okubaluleke ngakumbi, i-TU kunye ne-Arg zonyuse kakhulu umxholo we-chlorophyll, izinga le-photosynthetic elicocekileyo, kunye nezinga lokutshintshiselana kwegesi kwizithole zengqolowa phantsi koxinzelelo lwetyuwa. I-TU kunye ne-Arg ezisetyenziswa zodwa okanye xa zidibene zinokunyusa ukuqokelelana kwezinto ezomileyo nge-9.03–47.45%, kwaye ukwanda kwaba kukhulu xa zisetyenziswa kunye. Ukuqukumbela, olu phononongo lubonisa ukuba ukugcina i-redox homeostasis kunye ne-ion balance kubalulekile ekuphuculeni ukunyamezela kwezityalo kuxinzelelo lwetyuwa. Ukongeza, i-TU kunye ne-Arg zacetyiswa njengezinokwenzeka.abalawuli bokukhula kwezityalo,ingakumbi xa zisetyenziswa kunye, ukuphucula isivuno sengqolowa.
Utshintsho olukhawulezileyo kwimozulu nakwimisebenzi yezolimo luyandisa ukonakala kweenkqubo zezolimo1. Esinye seziphumo ezibi kakhulu kukwanda kwetyuwa emhlabeni, okusongela ukhuseleko lokutya kwihlabathi liphela2. Ukwanda kwetyuwa okwangoku kuchaphazela malunga ne-20% yomhlaba olimekayo kwihlabathi liphela, kwaye eli nani linokunyuka liye kwi-50% ngo-20503. Uxinzelelo lwetyuwa-alkali lunokubangela uxinzelelo lwe-osmotic kwiingcambu zezityalo, oluphazamisa ibhalansi ye-ionic kwisityalo4. Ezi meko zimbi zinokukhokelela ekuqhekekeni kwe-chlorophyll ngokukhawuleza, ukwehla kwamazinga e-photosynthesis, kunye nokuphazamiseka kwe-metabolic, ekugqibeleni okukhokelela ekunciphiseni isivuno sezityalo5,6. Ngaphezu koko, isiphumo esibi esiqhelekileyo kukwanda kokuveliswa kweentlobo ze-oxygen ezisebenzayo (ROS), ezinokubangela umonakalo we-oxidative kwii-biomolecules ezahlukeneyo, kubandakanya i-DNA, iiproteni, kunye ne-lipids7.
Ingqolowa (iTriticum aestivum) yenye yezona zityalo zibalulekileyo zengqolowa ehlabathini. Ayisosityalo sengqolowa esilinywa kakhulu kuphela kodwa ikwasisityalo esibalulekileyo sorhwebo8. Nangona kunjalo, ingqolowa inovelwano kwityuwa, nto leyo enokuthintela ukukhula kwayo, iphazamise iinkqubo zayo ze-physiological kunye ne-biochemical, kwaye inciphise kakhulu isivuno sayo. Amaqhinga aphambili okunciphisa iziphumo zoxinzelelo lwetyuwa aquka ukuguqulwa kwezakhi zofuzo kunye nokusetyenziswa kwabalawuli bokukhula kwezityalo. Izinto eziphilayo eziguqulwe ngokwezakhi zofuzo (i-GM) kukusetyenziswa kokuhlelwa kwezakhi zofuzo kunye nezinye iindlela zokuphuhlisa iintlobo zengqolowa ezinyamezela ityuwa9,10. Kwelinye icala, abalawuli bokukhula kwezityalo baphucula ukunyamezela ityuwa kwingqolowa ngokulawula imisebenzi ye-physiological kunye namanqanaba ezinto ezinxulumene netyuwa, ngaloo ndlela kuncitshiswa umonakalo woxinzelelo11. Ezi balawuli ngokubanzi zamkelwe kwaye zisetyenziswa kakhulu kuneendlela ze-transgenic. Zinokuphucula ukunyamezela kwezityalo kwiingcinezelo ezahlukeneyo ze-abiotic ezifana netyuwa, imbalela kunye neentsimbi ezinzima, kwaye zikhuthaze ukuhluma kwembewu, ukufunxwa kwezondlo kunye nokukhula kokuzala, ngaloo ndlela zonyusa isivuno sesityalo kunye nomgangatho.12 Abalawuli bokukhula kwezityalo babalulekile ekuqinisekiseni ukukhula kwesityalo kunye nokugcina isivuno kunye nomgangatho ngenxa yobuhlobo babo nokusingqongileyo, ukulula kokusetyenziswa, ukusebenza kakuhle kweendleko kunye nokusebenza. 13 Nangona kunjalo, ekubeni ezi modulators zineendlela ezifanayo zokusebenza, ukusebenzisa enye yazo kusenokungasebenzi. Ukufumana indibaniselwano yabalawuli bokukhula abanokuphucula ukunyamezela ityuwa kwingqolowa kubalulekile ekuveliseni ingqolowa phantsi kweemeko ezimbi, ukwandisa isivuno kunye nokuqinisekisa ukhuseleko lokutya.
Akukho zifundo ziphanda ukusetyenziswa okudibeneyo kwe-TU kunye ne-Arg. Akucaci ukuba olu didi lutsha lunokukhuthaza ukukhula kwengqolowa ngokusebenzisana phantsi koxinzelelo lwetyuwa. Ke ngoko, injongo yolu phononongo yayikukufumanisa ukuba aba balawuli bokukhula bababini banokunciphisa na imiphumo emibi yoxinzelelo lwetyuwa kwingqolowa. Ngenxa yesi sizathu, senze uvavanyo lwexesha elifutshane lwe-hydroponic wheat seedling ukuphanda iingenelo zokusetyenziswa okudibeneyo kwe-TU kunye ne-Arg kwingqolowa esebenzisana phantsi koxinzelelo lwetyuwa, sigxile kwi-redox kunye ne-ionic balance yezityalo. Sicinge ukuba udibaniso lwe-TU kunye ne-Arg lungasebenza ngokusebenzisana ukunciphisa umonakalo we-oxidative obangelwa luxinzelelo lwetyuwa kunye nokulawula ukungalingani kwe-ionic, ngaloo ndlela kuphucula ukunyamezela ityuwa kwingqolowa.
Umxholo we-MDA weesampuli umiselwe ngendlela ye-thiobarbituric acid. Linganisa ngokuchanekileyo i-0.1 g yomgubo wesampuli entsha, khupha nge-1 ml ye-10% ye-trichloroacetic acid imizuzu eli-10, u-centrifuge kwi-10,000 g imizuzu engama-20, uze uqokelele i-supernatant. I-extract ixutywe nomthamo olinganayo we-0.75% ye-thiobarbituric acid kwaye i-incubated kwi-100 °C imizuzu eli-15. Emva kokufakwa kwe-incubation, i-supernatant iqokelelwe nge-centrifugation, kwaye amaxabiso e-OD kwi-450 nm, 532 nm, kunye ne-600 nm alinganiswa. Uxinzelelo lwe-MDA lubalwe ngolu hlobo lulandelayo:
Ngokufanayo nonyango lweentsuku ezi-3, ukusetyenziswa kwe-Arg kunye ne-Tu nako kwandisa kakhulu imisebenzi ye-enzyme ye-antioxidant yezityalo zengqolowa phantsi konyango lweentsuku ezi-6. Ukudibanisa kwe-TU kunye ne-Arg kwakusasebenza kakhulu. Nangona kunjalo, kwiintsuku ezi-6 emva konyango, imisebenzi yee-enzyme ezine ze-antioxidant phantsi kweemeko ezahlukeneyo zonyango ibonise umkhwa wokwehla xa kuthelekiswa neentsuku ezi-3 emva konyango (Umfanekiso 6).
I-Photosynthesis sisiseko sokuqokelelwa kwezinto ezomileyo kwizityalo kwaye yenzeka kwii-chloroplast, ezibuthathaka kakhulu kwityuwa. Uxinzelelo lwetyuwa lunokukhokelela ekufakweni kwe-plasma membrane, ukuphazamiseka kwebhalansi ye-osmotic yeselula, umonakalo kwi-chloroplast ultrastructure36, kubangele ukubola kwe-chlorophyll, kunciphise umsebenzi wee-enzymes zomjikelo weCalvin (kuquka iRubisco), kwaye kunciphise ukudluliselwa kwe-electron ukusuka kwi-PS II ukuya kwi-PS I37. Ukongeza, uxinzelelo lwetyuwa lunokubangela ukuvalwa kwesisu, ngaloo ndlela kunciphise uxinano lwe-CO2 yamagqabi kwaye kuthintele i-photosynthesis38. Iziphumo zethu ziqinisekisile iziphumo zangaphambili zokuba uxinzelelo lwetyuwa lunciphisa ukuhamba kwesisu kwingqolowa, okubangela ukwehla kwesantya sokuphefumla kwamagqabi kunye noxinano lwe-CO2 ngaphakathi kweseli, okukhokelela ekugqibeleni ekuncipheni kwamandla e-photosynthetic kunye nokuncipha kwe-biomass yengqolowa (IiFig. 1 kunye ne-3). Okuphawulekayo kukuba, ukusetyenziswa kwe-TU kunye ne-Arg kunokuphucula ukusebenza kwe-photosynthetic kwezityalo zengqolowa phantsi koxinzelelo lwetyuwa. Ukuphuculwa kokusebenza kwe-photosynthetic kwakubaluleke kakhulu xa i-TU kunye ne-Arg zisetyenziswa ngaxeshanye (Umzobo 3). Oku kusenokuba kungenxa yokuba i-TU kunye ne-Arg zilawula ukuvulwa nokuvalwa kwesisu, ngaloo ndlela ziphucula ukusebenza kakuhle kwe-photosynthesis, okuxhaswa zizifundo zangaphambili. Umzekelo, uBencarti et al. bafumanise ukuba phantsi koxinzelelo lwetyuwa, i-TU yonyuse kakhulu ukuhamba kwesisu, izinga lokuhlanganiswa kwe-CO2, kunye nokusebenza kakuhle kwe-quantum ye-PSII photochemistry kwi-Atriplex portulacoides L.39. Nangona kungekho ngxelo zithe ngqo ezibonisa ukuba i-Arg inokulawula ukuvulwa nokuvalwa kwesisu kwizityalo ezivezwe kuxinzelelo lwetyuwa, uSilveira et al. babonise ukuba i-Arg inokukhuthaza ukutshintshiselana ngegesi kumagqabi phantsi kweemeko zembalela22.
Ngamafutshane, olu phononongo lubonisa ukuba nangona iindlela zazo zokusebenza ezahlukeneyo kunye neempawu ze-physicochemical, i-TU kunye ne-Arg zinokubonelela ngokumelana okufanayo noxinzelelo lwe-NaCl kwizithole zengqolowa, ingakumbi xa zisetyenziswa kunye. Ukusetyenziswa kwe-TU kunye ne-Arg kungenza inkqubo yokukhusela i-enzyme ye-antioxidant kwizithole zengqolowa isebenze, kunciphise umxholo we-ROS, kwaye kugcinwe uzinzo lwe-membrane lipids, ngaloo ndlela kugcinwe i-photosynthesis kunye ne-Na+/K+ balance kwizithole. Nangona kunjalo, olu phononongo lukwanemida; nangona isiphumo se-synergistic se-TU kunye ne-Arg siqinisekisiwe kwaye indlela yayo yokusebenza yomzimba ichazwe kwinqanaba elithile, indlela yokusebenza ye-molecular enzima ngakumbi ayicacanga. Ke ngoko, kufuneka uphando olongezelelweyo malunga nendlela ye-synergistic ye-TU kunye ne-Arg kusetyenziswa iindlela ze-transcriptomic, metabolomic kunye nezinye iindlela.
Iiseti zedatha ezisetyenzisiweyo kunye/okanye ezihlalutyiweyo ngexesha lophando lwangoku ziyafumaneka kumbhali ohambelanayo xa kuceliwe ngokufanelekileyo.
Ixesha leposi: Meyi-19-2025