Quantifying ATP turnover in anoxic coleoptiles of rice (Oryza sativa) demonstrates preferential allocation of energy to protein synthesis.
Quantifying ATP turnover in anoxic coleoptiles of rice (Oryza sativa) demonstrates preferential allocation of energy to protein synthesis.
复制标题
DOI：
10.1093/jxb/ers114
复制
发表时间：
2012-07
影响因子：
6.9
通讯作者：
Atwell BJ
中科院分区：
文献类型：
--
作者：
Edwards JM;Roberts TH;Atwell BJ
氧剥夺限制了细胞过程可用的能量，但没有全面的ATP预算已被报道的任何植物物种下的O2剥夺，包括水稻。以3d龄的O.在正常氧（通气溶液）、低氧（3%O2）和缺氧（N2）条件下生长的胚芽鞘中ATP再生的速率和（ii）蛋白质、脂质、核酸和细胞壁的合成速率以及K+运输的速率。基于已发表的生物能量学数据，然后比较了合成每类聚合物的成本和分配给每个过程的可用ATP的比例。蛋白质合成消耗的ATP合成的最大比例下，所有三个氧制度，分配给蛋白质合成的比例在缺氧（52%）的两倍以上，在常氧胚芽鞘（19%）。能量分配到细胞壁的合成是不减少缺氧，符合优先伸长典型的淹没胚芽鞘。脂质合成也保守强烈在O2赤字，这表明膜的完整性保持缺氧，从而使K+被保留在胚芽鞘细胞内。水稻品种胚芽鞘中的蛋白质合成速率与对比耐缺氧（包括发酵酶缺陷的突变体）证实，蛋白质的合成和营业额总是占大部分的ATP缺氧下消耗。它的结论是，成功建立水稻幼苗在水下很大程度上是由于胚芽鞘的能力，分配能量的重要过程，特别是蛋白质的合成。
Oxygen deprivation limits the energy available for cellular processes and yet no comprehensive ATP budget has been reported for any plant species under O2 deprivation, including Oryza sativa. Using 3-d-old coleoptiles of a cultivar of O. sativa tolerant to flooding at germination, (i) rates of ATP regeneration in coleoptiles grown under normoxia (aerated solution), hypoxia (3% O2), and anoxia (N2) and (ii) rates of synthesis of proteins, lipids, nucleic acids, and cell walls, as well as K+ transport, were determined. Based on published bioenergetics data, the cost of synthesizing each class of polymer and the proportion of available ATP allocated to each process were then compared. Protein synthesis consumed the largest proportion of ATP synthesized under all three oxygen regimes, with the proportion of ATP allocated to protein synthesis in anoxia (52%) more than double that in normoxic coleoptiles (19%). Energy allocation to cell wall synthesis was undiminished in hypoxia, consistent with preferential elongation typical of submerged coleoptiles. Lipid synthesis was also conserved strongly in O2 deficits, suggesting that membrane integrity was maintained under anoxia, thus allowing K+ to be retained within coleoptile cells. Rates of protein synthesis in coleoptiles from rice cultivars with contrasting tolerance to oxygen deficits (including mutants deficient in fermentative enzymes) confirmed that synthesis and turnover of proteins always accounted for most of the ATP consumed under anoxia. It is concluded that successful establishment of rice seedlings under water is largely due to the capacity of coleoptiles to allocate energy to vital processes, particularly protein synthesis.
登录
查看更多内容
影响因子：
4.2
作者：
FOX, TC;KENNEDY, RA;RUMPHO, ME
通讯作者：
RUMPHO, ME
影响因子：
6.9
作者：
Colmer, TD;Huang, SB;Greenway, H
通讯作者：
Greenway, H
影响因子：
7.3
作者：
Ishizawa, K;Murakami, S;Kuramochi, H
通讯作者：
Kuramochi, H
影响因子：
5.7
作者：
Kawano, N;Ella, E;Tanaka, K
通讯作者：
Tanaka, K
影响因子：
3.5
作者：
Kang, TJ;Yang, MS
通讯作者：
Yang, MS