- Tytuł:
- High light induced accumulation of two isoforms of the CF1 α-subunit in mesophyll and bundle sheath chloroplasts of C4 plants
- Autorzy:
-
Romanowska, Elżbieta
Powikrowska, Marta
Zienkiewicz, Maksymilian
Drożak, Anna
Pokorska, Berenika - Powiązania:
- https://bibliotekanauki.pl/articles/1040835.pdf
- Data publikacji:
- 2008
- Wydawca:
- Polskie Towarzystwo Biochemiczne
- Tematy:
-
bundle sheath
light intensity
C_4 subtypes
chloroplasts
CF_1 α-subunit isoforms
mesophyll
ATP synthase - Opis:
- The effect of light irradiance on the amount of ATP synthase α-subunit in mesophyll (M) and bundle sheath (BS) chloroplasts of C4 species such as maize (Zea mays L., type NADP-ME), millet (Panicum miliaceum, type NAD-ME) and guinea grass (Panicum maximum, type PEP-CK) was investigated in plants grown under high, moderate and low light intensities equal to 800, 350 and 50 µmol photons m-2 s-1, respectively. The results demonstrate that α-subunit of ATP synthase in both M and BS chloroplasts is altered by light intensity, but differently in the investigated species. Moreover, we identified two isoforms of the CF1 α-subunit, called α and ά. The CF1 α-subunit was the major isoform and was present in all light conditions, whereas ά was the minor isoform in low light. A strong increase in the level of the ά-subunit in maize mesophyll and bundle sheath thylakoids was observed after 50 h of high light treatment. The α and ά-subunits from investigated C4 species displayed apparent molecular masses of 64 and 67 kDa, respectively, on SDS/PAGE. The presence of the ά-subunit of ATPase was confirmed in isolated CF1 complex, where it was recognized by antisera to the α-subunit. The N-terminal sequence of ά-subunit is nearly identical to that of α. Our results indicate that both isoforms coexist in M and BS chloroplasts during plant growth at all irradiances. We suggest the existence in M and BS chloroplasts of C4 plants of a mechanism(s) regulating the ATPase composition in response to light irradiance. Accumulation of the ά isoform may have a protective role under high light stress against over protonation of the thylakoid lumen and photooxidative damage of PSII.
- Źródło:
-
Acta Biochimica Polonica; 2008, 55, 1; 175-182
0001-527X - Pojawia się w:
- Acta Biochimica Polonica
- Dostawca treści:
- Biblioteka Nauki
Artykuł