title: Systemic signalling in photosynthetic induction of Rumex K-1 (Rumex patientia × Rumex tianschaious) leaves.
abstract: 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.
authors.affiliation: State Key Laboratory of Crop Biology Shandong Key Laboratory of Crop Biology College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Hou
authors.forename: Li-Qiao
authors.initials: LQ
authors.lastname: Jin
authors.forename: Zi-Shan
authors.initials: ZS
authors.lastname: Zhang
authors.forename: Hui-Yuan
authors.initials: HY
authors.lastname: Gao
mesh_terms: D057486:Carbon Cycle / Q000502:physiology; D002245:Carbon Dioxide / Q000378:metabolism*; D008027:Light; D052585:Phloem / Q000502:physiology / Q000528:radiation effects; D010788:Photosynthesis / Q000502:physiology* / Q000528:radiation effects; D018515:Plant Leaves / Q000502:physiology* / Q000528:radiation effects; D031804:Rumex / Q000502:physiology* / Q000528:radiation effects; D015398:Signal Transduction / Q000502:physiology* / Q000528:radiation effects
chemical_list: D002245:Carbon Dioxide
keywords: carbon fixation; inside canopy; light fleck; non-dose-dependent; phloem; understory