Ithonya Lemvelo Emvelweni Yezitshalo
I-physiology yezitshalo ifunda ukuthi izitshalo zenza kanjani imisebenzi yazo yokuphila, kusukela ekumuncweni kwamanzi kanye nezakhamzimba, i-photosynthesis, ukuphefumula, ukukhula, kanye nokuzala. Azikho kulezi zinqubo ezenzeka endaweni engenalutho. Izitshalo zihlala endaweni ethile futhi zincike kakhulu ezimweni ezizungezile. Ngakho-ke, izinguquko ezicini zemvelo—njengokukhanya, izinga lokushisa, amanzi, izakhamzimba, amagesi omoya, umoya, kanye nosawoti—zithinta ngqo umsebenzi wezitho nezicubu zezitshalo. Lesi sihloko sixoxa ngendlela indawo ezungezile ebumba ngayo izimpendulo zomzimba zezitshalo, kokubili ngaphansi kwezimo ezinhle nangaphansi kokucindezeleka.
1. Ukukhanya: Umshayeli we-Photosynthesis kanye noMqondisi Wentuthuko
Ukukhanya kuyisici esiyinhloko esinquma izinga le-photosynthesis, inqubo lapho i-glucose yakhiwa khona kusuka ku-carbon dioxide namanzi ngosizo lwe-chlorophyll. Ukukhanya okwanele kuzokwandisa izinga le-photosynthesis kuze kufike ezingeni lokugcwala; ngemva kwalokho, ukukhanya okwengeziwe akusakhulisi i-photosynthesis ngoba ama-enzyme kanye nohlelo lokuthutha ama-electron kusebenza kahle. Uma amazinga okukhanya ephansi kakhulu, izitshalo zithola ukwakheka kwe-etiolation: iziqu ezinde, amaqabunga amancane, nombala okhanyayo ngenxa yokwakheka kwe-chlorophyll ephansi.
Ngaphandle kokuqina, ikhwalithi yokukhanya (ubude be-wave) nayo ibalulekile. Ukukhanya okubomvu nokuluhlaza okwesibhakabhaka kusebenza kakhulu kwi-photosynthesis. Okwamanje, isilinganiso sobomvu nokubomvu kakhulu (obomvu: okubomvu kakhulu) sithonya impendulo "yokugwema umthunzi" ezitshalweni ezikhula emthunzini. Ezimweni ezimnyama, izitshalo zivame ukwandisa iziqu zazo zifuna ukukhanya, zishintshe ukwakheka kwekhava yazo, futhi zabela izinsiza ezengeziwe ekukhuleni okuphezulu.
Ukukhanya kulawula ne-photoperiodism—impendulo yesitshalo emini nasebusuku—okunquma ukuqhakaza kwezinhlobo eziningi. Izitshalo zosuku olufushane ziyaqhakaza lapho ubusuku bubude, kuyilapho izitshalo zosuku olude zidinga izinsuku ezinde. Le ndlela iqinisekisa ukuthi ukuqhakaza kwenzeka ngesikhathi sesizini esihle kakhulu.
2. Izinga Lokushisa: Linquma Ijubane Lokusabela Kwe-Metabolic
Izinga lokushisa lithinta cishe zonke izinqubo zomzimba ngoba ukusabela kwamakhemikhali kuqhutshwa ama-enzyme. Ngaphakathi kwezinga lokushisa elifanele, ukuphefumula, i-photosynthesis, ukuhlukaniswa kwamaseli, kanye nokukhula kwamaseli kwenzeka kahle. Kodwa-ke, uma izinga lokushisa liphansi kakhulu, umsebenzi wama-enzyme uyancipha, ulwelwesi lwamaseli aluba lula ukuguquguquka, ukuthuthwa kwezinto kuyehla, futhi izitshalo zisengozini yokulimala okuvela kumakristalu eqhwa.
Ngakolunye uhlangothi, amazinga okushisa aphezulu kakhulu angabangela ukubola kwamaprotheni, aphazamise ulwelwesi, futhi andise ukuphefumula ngale kwe-photosynthesis. Ngenxa yalokho, izinqolobane zamandla ziphela ngokushesha okukhulu futhi ukukhula kwehla. Ezimweni ezishisayo nezomile, ama-stomata avame ukuvala ukuvimbela ukulahleka kwamanzi, kodwa lokhu kunciphisa ukumuncwa kwe-CO₂, ngaleyo ndlela kunciphisa i-photosynthesis.
Izitshalo nazo zinokuzivumelanisa nezimo zomzimba nezimo zokushisa, njengokukhiqizwa kwamaprotheni okushisa ashisa kakhulu emazingeni okushisa aphezulu ukuvikela izakhiwo zamaprotheni. Emazingeni okushisa aphansi, ezinye izitshalo zandisa amazinga azo kashukela oncibilikisiwe, zisebenza njenge-"antifreeze" yemvelo, yokwehlisa izinga lokubanda koketshezi lwamaseli.
3. Amanzi Nomswakama: Isihluthulelo Sokuthuthwa, Ukuthutha, Nokuphefumulela
Amanzi ayisici esiyinhloko samaseli kanye nendawo yokuthutha ku-xylem kanye ne-phloem. Ukutholakala kwamanzi kuthinta i-cell turgor, okunquma ukuqina kwezicubu kanye nekhono lamaseli lokukhula. Amanzi anele anikeza ingcindezi ephezulu ye-turgor, okuholela emaqabungeni aqhakazile. Ukuntuleka kwamanzi kubangela ukubuna, ukwehla kokukhula kwamaseli, kanye nokukhula okuntengantengayo.
Ukuhogela—ukuhwamuka kwamanzi nge-stomata—kusiza ekupholiseni amaqabunga futhi kushukumise ukugeleza kwamanzi kusuka ezimpandeni kuya emaqabunga. Kodwa-ke, ukuhogela ngokweqile ngaphandle kokunikezwa kwamanzi anele kungabangela ukucindezeleka kwesomiso. Ngaphansi kwalezi zimo, izitshalo zikhiqiza i-hormone i-abscisic acid (ABA), ebangela ukuvalwa kwe-stomatal. Ukuvalwa kwe-stomatal kunciphisa ukulahleka kwamanzi kodwa futhi kunciphisa ukungena kwe-CO₂, ngaleyo ndlela kunciphisa i-photosynthesis.
Umswakama nomoya nakho kudlala indima. Umoya owomile kanye nemimoya enamandla kwandisa izinga lokuphefumula, okwandisa ingozi yokubola komzimba, ikakhulukazi ezitshalweni ezincane noma lezo ezinezimpande ezingajulile.
4. Izakhamzimba Nezimo Zomhlabathi: Ukusekela Ukukhula Nokukhiqiza
Umhlabathi unikeza izakhamzimba ezinkulu (N, P, K, Ca, Mg, S) kanye nezakhamzimba ezincane (Fe, Mn, Zn, Cu, B, Mo, Cl, Ni) ezidingekayo ukuze kusetshenziswe i-metabolism. I-nitrogen ibalulekile ekwakhekeni kwe-chlorophyll kanye namaprotheni; i-phosphorus yamandla (ATP) kanye nama-nucleic acid; kanye ne-potassium yokulawula i-stomatal kanye nokusebenza kwe-enzyme. Ukuntuleka kwezakhamzimba kubangela izimpawu ezithile, njenge-chlorosis (ukuphuzi kwamaqabunga), i-necrosis, noma ukukhula okubambezelekile.
I-pH yomhlabathi ithinta ukutholakala kwezakhamzimba. Uma i-pH ine-asidi kakhulu, ezinye izakhi ezifana ne-Al ne-Mn zingaba yingozi, zivimbele ukukhula kwezimpande. Uma i-pH ine-alkaline kakhulu, izakhi ezifana ne-Fe ne-Zn kunzima ukuzimunca, okubangela ukuntuleka kwezitshalo noma ngabe inhlabathi inalezi zakhi.
Isakhiwo somhlabathi, umoya ovunguzayo, kanye nokugeleza kwamanzi nakho kunquma impilo yezimpande. Umhlabathi ogcwele amanzi unciphisa umoya-mpilo endaweni yezimpande, uphazamise ukuphefumula kwezimpande, unciphise ukumuncwa kwezakhamzimba, futhi okungenzeka kuholele ekuboleni kwezimpande. Izitshalo eziningi ziyasabela ezimweni ezingenayo i-oxygen ngokwakha i-aerenchyma (izikhala zomoya) ukusiza ukuthuthwa komoya-mpilo.
5. I-CO₂ kanye ne-O₂: Izinto Zokusetshenziswa Zokwenziwa Kwe-Photosynthesis Nokuphefumula
Ukuhlushwa kwe-CO₂ emoyeni kuhlobene ngqo ne-photosynthesis, ikakhulukazi ezitshalweni ze-C3 njengelayisi, ukolweni, kanye nobhontshisi. Ukwanda kwe-CO₂ kungandisa amazinga e-photosynthesis kanye nokusebenza kahle kokusetshenziswa kwamanzi ngoba i-stomata ayidingi ukuvula kabanzi ukuze ithole i-CO₂. Kodwa-ke, lezi zinzuzo zincike kwezinye izici ezifana nezakhamzimba kanye nokutholakala kwamanzi.
Umoya-mpilo uyadingeka ekuphefumuleni, inqubo yokuphula ushukela ube amandla. Enhlabathini ehlanganisiwe noma egcwele amanzi, ukuntuleka kwe-O₂ kuvimbela ukuphefumula kwezimpande, kunciphisa amandla atholakalayo okumunca nokukhula kwezakhamzimba. Ngaphansi kwezimo ezimbi kakhulu, izitshalo zishintshela ekuphefumuleni okungasebenzi kahle kwe-anaerobic futhi zikhiqize amakhemikhali angalimaza amaseli.
6. Usawoti: Ukuphazamiseka kwe-Osmotic kanye nobuthi be-Ion
Usawoti omningi—isibonelo, enhlabathini yasogwini noma ezindaweni eziniselwayo ezithola ukuqongelela usawoti—kubangela izinkinga ezimbili eziyinhloko. Okokuqala, ukucindezeleka kwe-osmotic: amanzi akuthola kunzima ukufinyelela ezimpandeni ngoba amandla amanzi enhlabathini ayancipha. Okwesibili, ubuthi be-ion: ukuqongelela kwe-Na⁺ ne-Cl⁻ kungalimaza ama-enzyme futhi kuphazamise ibhalansi yezakhamzimba, ikakhulukazi ukucindezela ukumuncwa kwe-K⁺, okubalulekile ekusebenzeni kweseli.
Izitshalo ze-halophytic (ezibekezelela usawoti) zinezindlela zokushintsha njengokugcina usawoti kuma-vacuoles, ukuba nezindlala zikasawoti ukuze zikhishwe, noma ukukhiqiza ama-osmolyte (i-proline, ushukela utshwala) ukuze kugcinwe ukulingana kwe-osmotic ngaphandle kokubhubhisa amaprotheni.
7. Izinto Ezingcolisayo Nokucindezeleka Kwezinto Eziphilayo: Amanxeba Angokomzimba Angabonakali Njalo
Imvelo ihlanganisa nokungcola nezinye izinto eziphilayo. I-ozone ye-tropospheric ingalimaza izicubu zamaqabunga futhi inciphise i-photosynthesis. Izinsimbi ezisindayo njenge-Pb, i-Cd, ne-Hg zingaphazamisa izinqubo ze-enzymatic futhi zibangele ukwakheka kwama-free radicals.
Ukusebenzisana namagciwane kanye nezilwane ezidla uhlaza kuthinta i-physiology ngokusebenzisa izinhlelo zokuzivikela. Izitshalo zikhiqiza amakhemikhali esibili (ama-alkaloid, ama-phenol, ama-terpenoid), ziqinisa izindonga zamaseli, futhi zilawula ama-hormone afana ne-jasmonic acid kanye ne-salicylic acid. Lezi zimpendulo zokuzivikela zidinga amandla, ngakho-ke ukuhwebelana kuvame ukwenzeka: ukukhula kuyahamba kancane njengoba ukuzivikela kukhula.
8. Ukuhlanganiswa Kwempendulo: Izitshalo Njengezinhlelo Ezizivumelanisa Nezimo
Eqinisweni, izici zemvelo azivamile ukusebenza zodwa. Isomiso sivame ukuhlotshaniswa namazinga okushisa aphezulu kanye nokukhanya okuphezulu; usawoti uvame ukuhlotshaniswa nokuntuleka kwamanzi; umthunzi uhlobene noshintsho lwekhwalithi yokukhanya. Izitshalo zisabela ngendlela ehlanganisiwe ngezibonakaliso zamahomoni, ukulawulwa kokubonakaliswa kwezakhi zofuzo, kanye nokulungiswa kwesakhiwo sezitho. Isibonelo, ngaphansi kwezimo ezomile, izitshalo azigcini nje ngokuvala ama-stomata azo kodwa futhi zinweba izimpande zazo, zinciphise indawo yamaqabunga azo, zijiye ama-cuticle azo, futhi zandise ukusebenza kahle kwazo kokusebenzisa amanzi.
Isiphetho
Imvelo inethonya elikhulu ku-physiology yezitshalo ngoba inquma ukutholakala kwamandla, amanzi, amagesi, kanye nezakhamzimba ezidingekayo empilweni. Ukukhanya kulawula i-photosynthesis kanye nentuthuko, izinga lokushisa lilawula izinga lokuguqulwa kwe-metabolic, amanzi athinta i-turgor kanye nokuphefumula, inhlabathi kanye nezakhamzimba kunquma umkhiqizo, kanti usawoti, ukungcola, kanye nokucindezeleka kwe-biotic kubangela izimpendulo eziguquguqukayo kanye nomonakalo. Ukuqonda lobu budlelwano kubalulekile kwezolimo, emahlathini, kanye nokongiwa kwemvelo, ikakhulukazi njengoba ushintsho lwesimo sezulu lwandisa imvamisa yokushisa okukhulu, isomiso, izikhukhula, kanye nokuwohloka komhlaba. Ulwazi nge-physiology yezitshalo lusenza sikwazi ukuklama amasu okulima kanye nokuphathwa kwemvelo agcina ukuqina kwezitshalo ngenkathi ekhulisa isivuno ngendlela eqhubekayo.
