Izilawuli zokukhula kwezitshalo (PGRs)ziyindlela engabizi kakhulu yokuthuthukisa ukuzivikela kwezitshalo ngaphansi kwezimo zokucindezeleka. Lolu cwaningo luphenye ikhono lababiliPGRs, i-thiourea (TU) ne-arginine (Arg), ukunciphisa ukucindezeleka kukasawoti ukolweni. Imiphumela yabonisa ukuthi i-TU ne-Arg, ikakhulukazi uma isetshenziswa ndawonye, ingalawula ukukhula kwezitshalo ngaphansi kwengcindezi kasawoti. Ukwelashwa kwabo kwandise kakhulu imisebenzi yama-enzyme e-antioxidant ngenkathi kuncipha amazinga ezinhlobo ze-oxygen esebenzayo (ROS), i-malondialdehyde (MDA), kanye nokuvuza kwe-electrolyte ehlobene (REL) ezitshalweni zikakolweni. Ukwengeza, lezi zindlela zokwelapha zehle kakhulu ukugxila kwe-Na+ ne-Ca2+ kanye nesilinganiso se-Na+/K+, kuyilapho kukhulisa kakhulu ukuhlushwa kwe-K+, ngaleyo ndlela kugcinwe ibhalansi ye-ion-osmotic. Okubaluleke nakakhulu, i-TU ne-Arg zandise kakhulu okuqukethwe kwe-chlorophyll, isilinganiso se-photosynthetic net, kanye nezinga lokushintshana kwegesi lezithombo zikakolweni ngaphansi kwengcindezi kasawoti. I-TU ne-Arg esetshenziswe iyodwa noma ihlangene ingakhuphula ukunqwabelana kwento eyomile ngo-9.03–47.45%, futhi ukwanda kwaba kukhulu lapho kusetshenziswa ndawonye. Sengiphetha, lolu cwaningo luqokomisa ukuthi ukugcinwa kwe-redox homeostasis kanye nebhalansi ye-ion kubalulekile ekuthuthukiseni ukubekezelelana kwezitshalo ekucindezelekeni kukasawoti. Ngaphezu kwalokho, i-TU ne-Arg yanconywa njengamandlaizilawuli zokukhula kwezitshalo,ikakhulukazi uma kusetshenziswa ndawonye, ukuthuthukisa isivuno sikakolweni.
Ukushintsha okusheshayo kwesimo sezulu kanye nezinqubo zezolimo kwandisa ukucekelwa phansi kwemvelo yezolimo1. Omunye wemiphumela emibi kakhulu ukugcwaliswa kukasawoti emhlabathini, okusongela ukuvikeleka kokudla emhlabeni wonke2. Ukufakwa kukasawoti emanzini okwamanje kuthinta cishe amaphesenti angu-20 omhlaba olimekayo emhlabeni wonke, futhi lesi sibalo singase sikhuphuke siye ku-50% ngo-20503. Ukucindezelwa kukasawoti-alkali kungabangela ingcindezi ye-osmotic ezimpandeni zezitshalo, okuphazamisa ibhalansi ye-ionic esitshalweni4. Izimo ezinjalo ezimbi zingase futhi ziholele ekuwohlokeni kwe-chlorophyll ngokushesha, ukwehla kwamazinga e-photosynthesis, kanye nokuphazamiseka kwe-metabolic, okuholela ekunciphiseni kwesivuno sezitshalo5,6. Ngaphezu kwalokho, umphumela onzima ovamile ukwanda kwesizukulwane sezinhlobo ze-oxygen esebenzayo (i-ROS), engabangela ukulimala kwe-oxidative kuma-biomolecules ahlukahlukene, okuhlanganisa i-DNA, amaprotheni, ne-lipids7.
Ukolweni (Triticum aestivum) ungenye yezitshalo ezisanhlamvu ezibaluleke kakhulu emhlabeni. Akusona nje kuphela isilimo secereal esilinywa kakhulu kodwa futhi siyisilimo esibalulekile sokuhweba8. Nokho, ukolweni uyazwela kusawoti, ongavimbela ukukhula kwawo, uphazamise izinqubo zawo zomzimba nezamakhemikhali ezinto eziphilayo, futhi unciphise kakhulu isivuno sawo. Amasu amakhulu okunciphisa imiphumela yokucindezeleka kukasawoti ahlanganisa ukuguqulwa kofuzo kanye nokusetshenziswa kwezilawuli zokukhula kwezitshalo. Izinto eziphilayo eziguqulwe ngofuzo (GM) ziwukusebenzisa ukuhlela izakhi zofuzo nezinye izindlela zokuthuthukisa ukolweni okwazi ukumelana nosawoti9,10. Ngakolunye uhlangothi, izilawuli zokukhula kwezitshalo zithuthukisa ukubekezelelana kukasawoti ukolweni ngokulawula imisebenzi yomzimba kanye namazinga ezinto ezihlobene nosawoti, ngaleyo ndlela kunciphise ukulimala kokucindezeleka11. Lezi zilawuli ngokuvamile zamukelwa kakhulu futhi zisetshenziswa kabanzi kunezindlela ze-transgenic. Angathuthukisa ukubekezelela kwezitshalo ekucindezelekeni okuhlukahlukene kwe-abiotic njengosawoti, isomiso nezinsimbi ezinzima, futhi akhuthaze ukuhluma kwembewu, ukutholwa kwezakhi kanye nokukhula kokuzala, ngaleyo ndlela kwandise isivuno nekhwalithi yezitshalo. 12 Izilawuli zokukhula kwezitshalo zibalulekile ekuqinisekiseni ukukhula kwezitshalo kanye nokugcina isivuno kanye nekhwalithi ngenxa yobungane bemvelo yazo, ukusebenziseka kalula, ukonga kwezindleko kanye nokuba ngokoqobo. 13 Kodwa-ke, njengoba lawa mamoduli enezinqubo ezifanayo zokwenza, ukusebenzisa eyodwa yawo kuphela kungase kungasebenzi. Ukuthola inhlanganisela yezilawuli zokukhula ezingathuthukisa ukubekezelela usawoti kukolo kubalulekile ekuzaleni ukolweni ngaphansi kwezimo ezimbi, ukwandisa isivuno kanye nokuqinisekisa ukutholakala kokudla.
Azikho izifundo eziphenya ukusetshenziswa okuhlangene kwe-TU ne-Arg. Akucaci ukuthi le nhlanganisela emisha ingakhuthaza ngokuhlanganyela ukukhula kukakolweni ngaphansi kwengcindezi kasawoti. Ngakho-ke, inhloso yalolu cwaningo kwakuwukunquma ukuthi lezi zilawuli ezimbili zokukhula zingakwazi yini ukunciphisa imiphumela emibi yokucindezeleka kukasawoti ukolweni. Kuze kube manje, senze ucwaningo lwesikhashana lwe-hydroponic kakolweni ukuze siphenye izinzuzo zokusetshenziswa okuhlangene kwe-TU ne-Arg ukolweni ngaphansi kokucindezeleka kukasawoti, sigxile ekulinganiseni kwe-redox ne-ionic yezitshalo. Sacabanga ukuthi inhlanganisela ye-TU ne-Arg ingasebenza ngokubambisana ukuze kuncishiswe umonakalo we-oxidative obangelwa ukucindezeleka kukasawoti futhi ilawule ukungalingani kwe-ionic, ngaleyo ndlela ithuthukise ukubekezelelana kukasawoti ukolweni.
Okuqukethwe kwe-MDA kwamasampuli kwanqunywa indlela ye-thiobarbituric acid. Kala ngokunembile u-0.1 g wempushana entsha yesampula, khipha ngo-1 ml ka-10% we-trichloroacetic acid imizuzu eyi-10, i-centrifuge ku-10,000 g imizuzu engama-20, bese uqoqa amandla amakhulu. I-extract ixutshwe nevolumu elinganayo ye-0.75% ye-thiobarbituric acid futhi yafakwa ku-100 °C imizuzu engu-15. Ngemuva kokufakwa, i-supernatant yaqoqwa nge-centrifugation, futhi amanani e-OD ku-450 nm, 532 nm, no-600 nm alinganiswa. Ukugxila kwe-MDA kubalwe ngale ndlela elandelayo:
Ngokufana nokwelashwa kwezinsuku ezi-3, ukusetshenziswa kwe-Arg ne-Tu nakho kwandisa kakhulu imisebenzi ye-enzyme ye-antioxidant yezithombo zikakolweni ngaphansi kokwelashwa kwezinsuku ezingu-6. Inhlanganisela ye-TU ne-Arg yayisasebenza kakhulu. Kodwa-ke, ezinsukwini ezingu-6 ngemva kokwelashwa, imisebenzi yama-enzyme amane e-antioxidant ngaphansi kwezimo ezihlukene zokwelashwa ibonise umkhuba wokuncipha uma kuqhathaniswa nezinsuku ze-3 ngemuva kokwelashwa (Umfanekiso 6).
I-photosynthesis iyisisekelo sokunqwabelana kwezinto ezomile ezitshalweni futhi ivela kuma-chloroplast, azwela kakhulu usawoti. Ukucindezeleka kukasawoti kungaholela ekwenziweni kwe-oxidation ye-plasma membrane, ukuphazamiseka kwebhalansi ye-osmotic yeselula, ukulimala kwe-chloroplast ultrastructure36, kubangele ukuwohloka kwe-chlorophyll, ukunciphisa umsebenzi wama-enzyme omjikelezo we-Calvin (kuhlanganise ne-Rubisco), futhi kunciphise ukudluliswa kwe-electron kusuka ku-PS II kuya ku-PS I37. Ngaphezu kwalokho, ukucindezeleka kukasawoti kungabangela ukuvalwa kwesisu, ngaleyo ndlela kunciphise ukugxila kweqabunga le-CO2 futhi kuvimbele i-photosynthesis38. Imiphumela yethu iqinisekise ukutholwa kwangaphambilini ukuthi ukucindezeleka kukasawoti kunciphisa ukuqhutshwa kwe-stomatal kukolweni, okuholela ekunciphiseni izinga lokuphefumula kweqabunga kanye nokuhlushwa kwe-CO2 ye-intracellular, okuholela ekugcineni ekunciphiseni umthamo we-photosynthetic kanye nokuncipha kwe-biomass kakolweni (Amakhiwane 1 no-3). Ngokuphawulekayo, uhlelo lwe-TU ne-Arg lungathuthukisa ukusebenza kahle kwe-photosynthetic kwezitshalo zikakolweni ngaphansi kwengcindezi kasawoti. Ukuthuthukiswa kokusebenza kahle kwe-photosynthetic kwakubaluleke kakhulu lapho i-TU ne-Arg isetshenziswa kanyekanye (Fig. 3). Lokhu kungase kube ngenxa yokuthi i-TU ne-Arg zilawula ukuvulwa nokuvala kwesisu, ngaleyo ndlela kuthuthukise ukusebenza kahle kwe-photosynthetic, okusekelwa izifundo zangaphambilini. Isibonelo, uBencarti et al. ithole ukuthi ngaphansi kokucindezeleka kukasawoti, i-TU yandise kakhulu ukuqhutshwa kwesisu, izinga lokulinganisa i-CO2, kanye nokusebenza kahle kwe-quantum ye-PSII photochemistry ku-Atriplex portulacoides L.39. Nakuba ingekho imibiko eqondile efakazela ukuthi i-Arg ingalawula ukuvulwa kwesisu nokuvala ezitshalweni ezivezwe ukucindezeleka kukasawoti, uSilveira et al. yabonisa ukuthi i-Arg ingakhuthaza ukushintshaniswa kwegesi emaqabungeni ngaphansi kwezimo zesomiso22.
Kafushane, lolu cwaningo luqokomisa ukuthi naphezu kwezindlela zabo ezihlukene zokwenza kanye nezakhiwo ze-physicochemical, i-TU ne-Arg inganikeza ukumelana okufaniswayo nokucindezeleka kwe-NaCl ezitshalweni zikakolweni, ikakhulukazi uma isetshenziswa ndawonye. Ukusetshenziswa kwe-TU ne-Arg kungenza kusebenze uhlelo lokuvikela i-enzyme ye-antioxidant yezithombo zikakolweni, kunciphise okuqukethwe kwe-ROS, futhi kugcinwe ukuzinza kwe-membrane lipids, ngaleyo ndlela kugcinwe i-photosynthesis kanye nebhalansi ye-Na +/K + ezitshalweni. Nokho, lolu cwaningo lubuye lube nemikhawulo; nakuba umphumela we-synergistic we-TU ne-Arg waqinisekiswa futhi indlela yayo yokuphila yachazwa ngezinga elithile, indlela yamangqamuzana eyinkimbinkimbi ihlala ingacacile. Ngakho-ke, ukutadisha okuqhubekayo kwendlela ye-synergistic ye-TU ne-Arg isebenzisa i-transcriptomic, i-metabolomic nezinye izindlela kuyadingeka.
Amasethi edatha asetshenzisiwe kanye/noma ahlaziywa phakathi nocwaningo lwamanje ayatholakala kumbhali ohambelanayo uma kunesicelo esifanele.
Isikhathi sokuthumela: May-19-2025