Role of bundle sheath conductance in sustaining photosynthesis competence in sugarcane plants under nitrogen deficiency

Autor(es)

Tofanello, Vanessa R. ^[1] ; Andrade, Larissa M. ^[2] ; Flores-Borges, Denisele N. A. ^[1] ; Kiyota, Eduardo ^[1] ; Mayer, Juliana L. S. ^[1] ; Creste, Silvana ^[2] ; Machado, Eduardo C. ^[3] ; Yin, Xinyou ^[4] ; Struik, Paul C. ^[4] ; Ribeiro, Rafael V. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Campinas UNICAMP, Inst Biol, Lab Crop Physiol LCroP, Dept Plant Biol, Campinas, SP - Brazil

^[2] Inst Agron IAC, Ctr Cana, Ribeirao Preto, SP - Brazil

^[3] IAC, Ctr Res & Dev Ecophysiol & Biophys, Lab Plant Physiol Coaracy M Franco, Campinas, SP - Brazil

^[4] Wageningen Univ & Res, Dept Plant Sci, Ctr Crop Syst Anal, Wageningen - Netherlands

• Tipo de documento: Artigo Científico
• Fonte: PHOTOSYNTHESIS RESEARCH; v. 149, n. 3, p. 275-287, SEP 2021.
• Citações Web of Science: 2

Resumo

The role of bundle sheath conductance (g(bs)) in sustaining sugarcane photosynthesis under nitrogen deficiency was investigated. Sugarcane was grown under different levels of nitrogen supply and g(bs) was estimated using simultaneous measurements of leaf gas exchange and chlorophyll fluorescence at 21% or 2% {[}O-2] and varying air {[}CO2] and light intensity. Maximum rates of PEPC carboxylation, Rubisco carboxylation, and ATP production increased with an increase in leaf nitrogen concentration (LNC) from 1 to 3 g m(-2). Low nitrogen supply reduced Rubisco and PEPC abundancies, the quantum efficiency of CO2 assimilation and g(bs). Because of reduced g(bs), low photosynthetic rates were not associated with increased leakiness under nitrogen deficiency. In fact, low nitrogen supply increased bundle sheath cell wall thickness, probably accounting for low g(bs) and increased estimates of {[}CO2] at Rubisco sites. Effects of nitrogen on expression of ShPIP2;1 and ShPIP1;2 aquaporins did not explain changes in g(bs). Our data revealed that reduced Rubisco carboxylation was the main factor causing low sugarcane photosynthesis at low nitrogen supply, in contrast to the previous report on the importance of an impaired CO2 concentration mechanism under N deficiency. Our findings suggest higher investment of nitrogen into Rubisco protein would favour photosynthesis and plant performance under low nitrogen availability. (AU)

• Processo FAPESP: 08/57495-3 - Integrando características fisiológicas, morfológicas e anatômicas para entender o rendimento diferencial de sacarose em genótipos de cana-de-açúcar
• Beneficiário: Eduardo Caruso Machado
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Temático
• Processo FAPESP: 17/12302-2 - Revelando as causas da ineficiência fotossintética da cana-de-açúcar sob baixa disponibilidade de nitrogênio
• Beneficiário: Rafael Vasconcelos Ribeiro
• Modalidade de apoio: Bolsas no Exterior - Pesquisa