Changes in the Chlorophyll Contents of Leaves and in Levels of Cytokinins in Root Exudates during Ripening of Rice Cultivars Nipponbare and Akenohoshi

Effects of Soil Temperature on Growth and Root Function in Rice

“…In addition, increased levels of ABA and decreased levels of cytokinins in shoots were observed when shoot growth was retarded at high soil temperatures in grass (Liu and Huang, 2005). Cytokinin was associated with the maintenance of photosynthetic rate in rice (Ookawa et al, 2004;San-oh et al, 2006;Soejima et al, 1992Soejima et al, , 1995. Then, in this study, the interactive effect of ABA and cytokinins would relate to the decrease in photosynthesis, which contribute to the decline in dry weight of shoot and root under high soil temperature stress.…”

A Comparison of the Accumulation and Partitioning of Nitrogen in Plants between Two Rice Cultivars, Akenohoshi and Nipponbare, at the Ripening Stage

“…It suppresses the senescence of lower leaves, in particular Uordi et al, 2000). The amounts of cytokinin transported from the roots to the above-ground parts of plants grown in the field are larger in Akenohoshi than in Nipponbare (Soejima et aI., 1992;Soejima et al, 1995).…”

Analysis of the Factors Causing Differences in the Leaf-Senescence Pattern between Two Soybean Cultivars, Enrei and Tachinagaha: Comparison of root length and exudation rate among grafted plants

“…Hirasawa et al (1983) demonstrated that the exudation rate, an indicator of the physiologi-:::al activity of roots, decreased as leaf tissue aged. Jiang et al (1988) and Soejima et al (1995) reported that the exudation rate for rice cultivars with slow leaf senescence :J.fter heading was greater than that of varieties with more rapid senescence. Jiang et al (1994) reported a relation>hip between the reduction in exudation rate and the rapidity of leaf senescence in paddy rice with rotten roots.…”

“…The amount of cytokinins, synthesized in the roots and transported to the shoots, is large in plants with a high exudation rate (soybean, rice, wheat, sorghum); (Nooden et al, 1990;Ambler et al, 1992;Soejima et al, 1995;Hirasawa et al, 1997;Ookawa et al, 1999b). There is also a close relationship between the nitrogen content and leaf senescence (Makino et al, 1984).…”