Schönfeld M, Yaacoby T, Michael O, Rubin B
Department of Agricultural Botany, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot 76100, Israel.
Plant Physiol. 1987 Feb;83(2):329-33. doi: 10.1104/pp.83.2.329.
A triazine-resistant (R) biotype of Phalaris paradoxa L. (hood canarygrass) was superior to a triazine-susceptible (S) biotype in seed-germinability and seedling emergence. It was equal or superior to the S-biotype in growth under noncompetitive conditions. Rates of CO(2) uptake by R-plants were similar to those of S-plants, except at very low photon flux densities, where S-plants exhibited higher rates of CO(2) uptake. Fluorescence induction curves of chloroplasts isolated from R-plants indicated an alteration in photosystem II. Analysis of the light dependence of electron transport shows a reduction in quantum yield (Q(y)) in R- compared to S-chloroplasts. The same analysis, however, shows for R-chloroplasts an increase in the light-saturated electron transport rate (V(max)). The increase in V(max) compensates for the reduction of Q(y) over a wide range of photon flux densities, which may explain the similarity between R- and S-biotypes in photosynthetic potential and growth.
抗三嗪（R）生物型的奇异虉草（Phalaris paradoxa L.，黑麦草）在种子发芽率和幼苗出土方面优于感三嗪（S）生物型。在非竞争条件下生长时，它与S生物型相当或更优。R型植株的CO₂吸收速率与S型植株相似，只是在极低的光子通量密度下，S型植株表现出更高的CO₂吸收速率。从R型植株分离的叶绿体的荧光诱导曲线表明光系统II发生了改变。对电子传递的光依赖性分析表明，与S型叶绿体相比，R型叶绿体的量子产率（Q(y)）降低。然而，同样的分析表明R型叶绿体的光饱和电子传递速率（V(max)）增加。V(max)的增加在很宽的光子通量密度范围内补偿了Q(y)的降低，这可能解释了R型和S型生物型在光合潜力和生长方面的相似性。
