Maize leaves turn away from neighbors.
In commercial crops, maize (Zea mays) plants are typically grown at a larger distance between rows (70 cm) than within the same row (16-23 cm). This rectangular arrangement creates a heterogeneous environment in which the plants receive higher red light (R) to far-red light (FR) ratios from the interrow spaces. In field crops, the hybrid Dekalb 696 (DK696) showed an increased proportion of leaves toward interrow spaces, whereas the experimental hybrid 980 (Exp980) retained random leaf orientation. Mirrors reflecting FR were placed close to isolated plants to simulate the presence of neighbors in the field. In addition, localized FR was applied to target leaves in a growth chamber. During their expansion, the leaves of DK696 turned away from the low R to FR ratio signals, whereas Exp980 leaves remained unaffected. On the contrary, tillering was reduced and plant height was increased by low R to FR ratios in Exp980 but not in DK696. Isolated plants preconditioned with low R/FR-simulating neighbors in a North-South row showed reduced mutual shading among leaves when the plants were actually grouped in North-South rows. These observations contradict the current view that phytochrome-mediated responses to low R/FR are a relic from wild conditions, detrimental for crop yield.
Maddonni
Gustavo Angel
GA
Departamento de Producción Vegetal, Universidad de Buenos Aires, Avenue San Martín 4453, C1417DSE, Buenos Aires, Argentina. maddonni@agro.uba.ar
Otegui
María Elena
ME
Andrieu
Bruno
B
Chelle
Michael
M
Casal
Jorge J
JJ
D000222:Adaptation, Physiological / Q000502:physiology / Q000528:radiation effects; D004463:Ecology; D004780:Environment, Controlled; D018506:Gene Expression Regulation, Plant; D008027:Light; D010834:Phytochrome / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000254:growth & development / Q000502:physiology* / Q000528:radiation effects; D018547:Plant Stems / Q000254:growth & development / Q000502:physiology / Q000528:radiation effects; D015398:Signal Transduction / Q000502:physiology / Q000528:radiation effects; D013045:Species Specificity; D003313:Zea mays / Q000254:growth & development / Q000502:physiology* / Q000528:radiation effects
D010834:Phytochrome