Resumo

SERRANO, Alejandro; MALDONADO, M. Belén  e  BOCCALANDRO, Hernán. Inflorescence stems of Arabidopsis thaliana bend away from neighbours through a response controlled by phytochrome B. Multequina [online]. 2017, vol.26, n.1, pp.05-19. ISSN 1852-7329.

Plants are able to detect the presence of neighbours by sensing the variation in the proportion of red and far red light (around 660 nm and 740 nm, respectively) in their surrounding ambient. The phytochromes are the main photoreceptors involved in neighbour detection, and regulate several physiological processes that modulate plant shape and architecture, enabling plants to compete for light by growing over the surrounding vegetation. The state of knowledge about this kind of responses in flowers and inflorescences is scarce compared to what is known in vegetative organs. In this context, we aimed to evaluate growth and bending responses of inflorescence stems induced by a unilateral signal of neighbours in Arabidopsis thaliana (L.). We carried out experiments employing natural canopies and artificial far red light sources inside a greenhouse where UV-Blue region of the sunlight spectrum was excluded. We report for the fist time a lateral escape in terms of a bending response of the stem against the signal of neighbours, which is promoted by phytochrome B. Our results combined with pre-existing data may contribute to better understand the behaviour of flowering plants growing in patches, providing a new perspective of shade avoidance responses in terms of its effect in reproductive biology.

Palavras-chave : Shade avoidance; Inflorescence; Far red; Phytochromes.

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