Portal de Periódicos da CAPES

Artigo Acesso aberto Produção Nacional Revisado por pares

BIBTEX RIS

Deficiency in phytochromobilin biosynthesis enhances heat-stress-induced impairments to the photosynthetic apparatus in tomato

2018; Institute of Experimental Botany of the Czech Academy of Sciences; Volume: 63; Issue: 1 Linguagem: Inglês

10.32615/bp.2019.016

1573-8264

Ailton José Crispim Filho, Alan Carlos Costa, Frederico Rocha Rodrigues Alves, Priscila Ferreira Batista, Arthur Almeida Rodrigues, Sebastião Carvalho Vasconcelos Filho, Kelly Juliane Telles Nascimento,

Plant responses to elevated CO2

Plants are continuously exposed to unfavorable environmental conditions, such as heat stress, which negatively affect plant growth and productivity. There is evidence that phytochromes are involved in plant response to different abiotic stresses. We investigated the possible phytochrome-dependent responses to heat stress in photomorphogenic tomato mutants aurea (au, phytochromobilin-deficient, PΦB) and high-pigment 1 (hp1, hyperresponsive to phytochrome-mediated responses), as well as the wild-type Micro-Tom (MT). In comparison with MT, reductions in photosynthetic rate promoted by a high temperature were more pronounced in au, whereas less pronounced in hp1. All genotypes subjected to the heat stress exhibited adjustments in the capture and dissipation of energy, which were indicated by increases in the initial fluorescence and decreases in the maximum photochemical efficiency of photosystem II (PS II). The effective quantum yield of PS II and the apparent electron transport rate showed greatest alterations in the au mutant. In addition, heat-triggered anatomical changes occurred in all genotypes but were most conspicuous in the au mutant, followed by MT. Thus, phytochrome-dependent mechanisms played pivotal roles in the plant responses to the heat stress, and deficiency in phytochromobilin biosynthesis enhanced the heat-induced impairment of photosynthetic performance.