A mutation that eliminates bundle sheath extensions reduces leaf hydraulic conductance, stomatal conductance and assimilation rates in tomato (Solanum lycopersicum)

Autor(es)

Zsoegoen, Agustin ^[1] ; Alves Negrini, Ana Clarissa ^{[2, 3]} ; Pereira Peres, Lazaro Eustaquio ^[1] ; Nguyen, Hoa Thi ^[4] ; Ball, Marilyn C. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Ciencias Biol, Escola Super Agr Luiz de Queiroz, BR-13418900 Piracicaba, SP - Brazil

^[2] Embrapa Hortalicas, BR-70359970 Brasilia, DF - Brazil

^[3] Australian Natl Univ, Res Sch Biol, Plant Sci Div, Canberra, ACT 0200 - Australia

^[4] Hoa Thi Nguyen, Australian Natl Univ, Res Sch Biol, Plant Sci Div, Canberra, ACT 0200 - Australia

• Tipo de documento: Artigo Científico
• Fonte: NEW PHYTOLOGIST; v. 205, n. 2, p. 618-626, JAN 2015.
• Citações Web of Science: 17

Resumo

Bundle sheath extensions (BSEs) are key features of leaf structure whose distribution differs among species and ecosystems. The genetic control of BSE development is unknown, so BSE physiological function has not yet been studied through mutant analysis. We screened a population of ethyl methanesulfonate (EMS)-induced mutants in the genetic background of the tomato (Solanum lycopersicum) model Micro-Tom and found a mutant lacking BSEs. The leaf phenotype of the mutant strongly resembled the tomato mutant obscuravenosa (obv). We confirmed that obv lacks BSEs and that it is not allelic to our induced mutant, which we named obv-2. Leaves lacking BSEs had lower leaf hydraulic conductance and operated with lower stomatal conductance and correspondingly lower assimilation rates than wild-type leaves. This lower level of function occurred despite similarities in vein density, midvein vessel diameter and number, stomatal density, and leaf area between wild-type and mutant leaves, the implication being that the lack of BSEs hindered water dispersal within mutant leaves. Our results comparing near-isogenic lines within a single species confirm the hypothesised role of BSEs in leaf hydraulic function. They further pave the way for a genetic model-based analysis of a common leaf structure with deep ecological consequences. (AU)

• Processo FAPESP: 13/11541-2 - Interação entre auxina e a família gênica do florígeno no controle da arquitetura e produtividade de tomateiro (Solanum lycopersicum L.)
• Beneficiário: Agustin Zsögön
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado