Rosner A, Gressel J, Jakob K M
Biochim Biophys Acta. 1977 Feb 3;474(3):386-97. doi: 10.1016/0005-2787(77)90268-4.
The effects of metabolic shifts on nucleic acid syntheses have been widely studied in prokaryotes, but not in plants because of a paucity of suitable systems. Spirodela (Duckweed) was thus used to ascertain the response of the nucleocytoplasmic (nc) and plastid ribosomal RNA metabolisms to partial and total carbon deprivation. The 0.56 X 10(6) Mr plastid rRNA is the one species of RNA most affected by metabolic shifts; unlike other species, its appearance is delayed by deprivation and it appears more rapidly than other species on transfer from dark to light. The data suggest a discoordination between the transcription and processing of plastid ribosomal precursors. Incorporation into all nc and plastid rRNAs was severely reduced and all rRNA precursors accumulated in green plants that were completely deprived of carbon by transferring to the dark, without sucrose. The amounts of nc and plastid precursors transcribed readjusted to the reduced amounts processed to mature RNA only after long periods in the dark with sucrose. This delay involved the formation of new colorless plants. Less plastid RNAs, compared to nc RNAs are found in the dark steady state.
代谢转变对核酸合成的影响在原核生物中已得到广泛研究，但由于缺乏合适的系统，在植物中尚未开展此类研究。因此，利用浮萍来确定核质（nc）和质体核糖体RNA代谢对部分和完全碳剥夺的反应。0.56×10⁶Mr质体rRNA是受代谢转变影响最大的一种RNA；与其他种类不同，其出现会因剥夺而延迟，并且从黑暗转移到光照时，它比其他种类出现得更快。数据表明质体核糖体前体的转录和加工之间存在失调。在完全剥夺碳（通过转移到黑暗中且不添加蔗糖）的绿色植物中，所有nc和质体rRNA的掺入都严重减少，所有rRNA前体都积累。只有在黑暗中添加蔗糖长时间培养后，转录的nc和质体前体数量才重新调整到加工成成熟RNA的减少量。这种延迟涉及新的无色植物的形成。在黑暗稳态下，与nc RNA相比，质体RNA较少。
