Nthaka

Inapangidwadi Mwaluso

▪ Mgwirizano wodabwitsa womwe ulipo pakati pa zomera zina ndi mabakiteriya m’nthaka umathandiza zamoyo.

Taganizirani izi: Nayitirojeni ndi wofunika kwambiri kuti zomera zikule ndi kubereka. Koma nayitirojeni amafunika kusinthidwa kuchoka pa mpweya kukhala mchere monga amoniya, kuti zomerazo zithe kuugwiritsa ntchito. Mbewu za m’gulu la nyemba zimathetsa vutoli mwa kugwirira ntchito limodzi ndi mabakiteriya otchedwa rhizobia. Mgwirizano wothandizanawu pakati pa zinthu ziwiri zosiyana, umatchedwa symbiosis.

Pogwiritsa ntchito mankhwala enaake, mbewu za m’gulu la nyemba zimakopa mabakiteriya, ndipo mabakiteriyawo amalowa m’mitsitsi ya mbewuzo. Ngakhale kuti mbewuzi ndi mabakiteriyawa ndi zosiyana kwambiri, izo zimagwira ntchito mogwirizana “kupanga chinthu chatsopano: mphundu ku mitsitsi, imene imagwira ntchito yosintha nayitirojeni.” (Natural History) Mabakiteriyawa akalowa mkati mwa mphunduyi, yomwe imakhala shopu komanso nyumba yawo yatsopano, amayamba ntchito yawo. Chida chawo chachikulu chimene amagwiritsa ntchito ndi mtundu winawake wa puloteni wotchedwa nitrogenase, amene amamugwiritsa ntchito kusintha nayitirojeni wopezeka mu mpweya wa m’nthaka.

Magazini ya Natural History imati: “Nitrogenase yense amene amapezeka pa dziko lapansi . . . angakwane mu chitini chimodzi chachikulu.” Choncho, molekyu iliyonse ndi yofunika kwambiri. Koma pali vuto limodzi. Nitrogenase amawonongedwa ndi okosijeni. Pofuna kuthetsa vuto limeneli, mbewu za m’gulu la nyemba zimatulutsa zinthu zinazake zomwe zimachotsa okosijeni wosafunikira amene angathe kuwononga nitrogenase.

Kakhungu kokuta mphundu kamathandiza kuti mbewuyo ndi mabakiteriya zizipatsirana mchere wa amoniya, shuga ndi zinthu zina zofunikira. Koma mofanana ndi mbewu zina zonse, mbewu za m’gulu la nyemba zimafa. Zikatero, mchere wa amoniya umatsala m’nthaka. Motero, m’pake kuti mbewu za m’gulu la nyemba zimatchedwa “zomera zokhala ndi manyowa.”

Ndiyeno kodi inuyo mukuganiza bwanji? Kodi mabakiteriya ndiponso zomera zimene amagwira nazo ntchito zinangolota, n’kupanga dongosolo lochirikiza moyo lodabwitsali, kapena umenewu ndi umboni winanso wakuti zinachita kulengedwa?

[Chithunzi patsamba 25]

Mphundu

[Mawu a Chithunzi patsamba 25]

Background: © Wally Eberhart/Visuals Unlimited; inset: © Dr. Jack M. Bostrack/Visuals Unlimited