| Texto completo | |
| Autor(es): |
Nascimento, Alex
[1]
;
Suguiyama, Vanessa Fuentes
[1]
;
Esteves Sanches, Rodrigo Fazani
[2]
;
Braga, Marcia R.
[2]
;
da Silva, Emerson Alves
[2]
;
Naldi Silva, Joao Paulo
[1]
;
Centeno, Danilo C.
[1]
Número total de Autores: 7
|
| Afiliação do(s) autor(es): | [1] Univ Fed ABC UFABC, Ctr Ciencias Nat & Humanas, Alameda Univ S-No, BR-09606045 Sao Bernardo Do Campo, SP - Brazil
[2] Inst Bot Secretaria Infraestrutura & Meio Ambient, Nucleo Pesquisa Fisiol & Bioquim, Ave Miguel Stefano 3687, BR-04301902 Sao Paulo, SP - Brazil
Número total de Afiliações: 2
|
| Tipo de documento: | Artigo Científico |
| Fonte: | FLORA; v. 267, JUN 2020. |
| Citações Web of Science: | 0 |
| Resumo | |
Desiccation tolerance (DT) in vegetative tissues is not a common ability, especially in Angiosperms. Barbacenia genus is distributed in tropical seasonally dry environments, such as rock outcrops, in South America. Some of the Barbacenia species are described as DT and are able to tolerate drastic water loss of their tissues during the desiccation process and to reestablish their metabolism after rehydration. In order to better understand this ability, we evaluated aspects related to leaf water status, gas exchange, photosynthetic pigments content and chlorophyll a fluorescence of B. graminifolia, during 32 days of water deprivation followed by rehydration. Carbon assimilation (A) remained active until the 24th day, when volumetric soil moisture was below 10%. Leaf relative water content (RWC) remained constant during 28 days of water withholding, decreasing significantly after this period, followed by the lowest gas exchange parameters and maximum quantum efficiency of photosystem II (Fv/Fm), and the highest degradation rates of chlorophyll and carotenoids in the course of the desiccation period. After rehydration, RWC was rapidly recovered, as well as Fv/Fm and photosynthetic parameters. This time frame was not enough for total recovery of A rates due, probably, to the slow restoration of chlorophyll a content. We classify, therefore, the species as a resurrection plant. Despite the similar decrease of photosynthetic rates found in other DT species before reaching the desiccated state, B. graminifolia maintains CO2 assimilation even under low soil water availability (10%) as physiological strategy when submitted to severe water deficit. (AU) | |
| Processo FAPESP: | 12/23838-7 - Alteração no balanço de carbono em gramíneas visando incremento na produção de açúcares |
| Beneficiário: | Danilo da Cruz Centeno |
| Modalidade de apoio: | Auxílio à Pesquisa - Programa BIOEN - Jovens Pesquisadores |
| Processo FAPESP: | 12/16332-0 - Carboidratos de reserva e de parede celular de plantas e de fungos filamentosos: alterações em resposta a aleloquímicos e a variações ambientais |
| Beneficiário: | Marcia Regina Braga |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |