State Key Laboratory of Crop Biology Shandong Key Laboratory of Crop Biology College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China.
Plant Cell Environ. 2015 Apr;38(4):685-92. doi: 10.1111/pce.12427. Epub 2014 Oct 1.
The rapid induction of photosynthesis is critical for plants under light-fleck environment. Most previous studies about photosynthetic induction focused upon single leaf, but they did not consider the systemic integrity of plant. Here, we verified whether systemic signalling is involved in photosynthetic induction. Rumex K-1 (Rumex patientia × Rumex tianschaious) plants were grown under light-fleck condition. After whole night dark adaptation, different numbers of leaves (system leaf or SL) were pre-illuminated with light, and then the photosynthetic induction of other leaves (target leaf or TL) was investigated. This study showed that the pre-illumination of SL promoted photosynthetic induction in TL. This promotion was independent of the number of SL, the light intensity on SL and the distance between SL and TL, indicating that this systemic signalling is non-dose-dependent. More interestingly, the photosynthetic induction was promoted by only the pre-illumination of morphological upper leaf rather than the pre-illumination of morphological lower leaf, indicating that the transfer of this signal is directional. The results showed that the transfer of this systemic signalling depends upon the phloem. This systemic signalling helps plants to use light energy more efficiently under light flecks.
快速诱导光合作用对光斑环境下的植物至关重要。大多数先前关于光合作用诱导的研究都集中在单个叶片上，但它们没有考虑植物的系统完整性。在这里，我们验证了系统信号是否参与光合作用诱导。Rumex K-1（野荞麦 × 长白猪牙花）植物在光斑条件下生长。经过整夜的暗适应后，用光照预照不同数量的叶片（系统叶或 SL），然后研究其他叶片（靶叶或 TL）的光合作用诱导。本研究表明，SL 的预照促进了 TL 中的光合作用诱导。这种促进与 SL 的数量、SL 上的光强以及 SL 和 TL 之间的距离无关，表明这种系统信号是非剂量依赖性的。更有趣的是，只有形态上的上部叶片的预照促进了光合作用的诱导，而不是形态上的下部叶片的预照，这表明这种信号的传递是有方向性的。结果表明，这种系统信号的传递依赖于韧皮部。这种系统信号有助于植物在光斑下更有效地利用光能。
