caa a22 4500 605480486 CHVBK 20210128100415.0 cr unu---uuuuu 210128e20150301xx s 000 0 eng 10.1007/s11099-015-0074-9 doi (NATIONALLICENCE)springer-10.1007/s11099-015-0074-9 Water-deficiency effects on single leaf gas exchange and on C4 pathway enzymes of maize genotypes with differing abiotic stress tolerance [Elektronische Daten] [R. Sicher, J. Bunce, J. Barnaby, B. Bailey] Responses to drought were studied using two maize inbred lines (B76 and B106) and a commercial maize hybrid (Zea mays L. cv. Silver Queen) with differing resistance to abiotic stress. Maize seedlings were grown in pots in controlled environment chambers for 17 days and watering was withheld from one half the plants for an additional 11 days. On the final treatment date, leaf water potentials did not differ among genotypes and were −0.84 and −1.49 MPa in the water sufficient and insufficient treatments, respectively. Greater rates of CO2 assimilation were retained by the stress tolerant maize inbred line, B76, in comparison to the other two genotypes 11 days after watering was withheld. Rates of CO2 assimilation for all three genotypes were unaffected by decreasing the measurement O2 concentration from 21 to 2% (v/v). Activities of phosphoenolpyruvate carboxylase (PEPC), NADP-malic enzyme (NADP-ME), and NADP malate dehydrogenase were inhibited from 25 to 49% by the water deficiency treatment. Genotypic differences also were detected for the activities of NADP-ME and for PEPC. Changes of transcript abundance for the three C4 pathway enzymes also varied among watering treatments and genotypes. However, examples where transcripts decreased due to drought were associated with the two stress susceptible genotypes. The above results showed that enzymes in the C4 photosynthetic pathway were less inhibited by drought in stress tolerant compared to stress susceptible maize genotypes. The Institute of Experimental Botany, 2015 C4 photosynthesis nationallicence drought nationallicence enzyme activities nationallicence gene expression nationallicence phospho enol pyruvate carboxylase nationallicence g s (21) : stomatal conductance at 21% O2 nationallicence g s (2) : stomatal conductance at 2% O2 nationallicence NADP-MDH : NADP-dependent malate dehydrogenase nationallicence NADP-ME : NADP-dependent malic enzyme nationallicence PEPC : phosphoenolpyruvate carboxylase nationallicence P N(21) : net photosynthetic rates at 21% O2 nationallicence P N(2) : net photosynthetic rates at 2% O2 nationallicence Ψw : leaf water potential nationallicence Sicher R. Crop System and Global Change Laboratory, USDA-ARS, Building 001, Room 342, BARC-west, 10300 Baltimore Avenue, 20705, Beltsville, MD, USA aut Bunce J. Crop System and Global Change Laboratory, USDA-ARS, Building 001, Room 342, BARC-west, 10300 Baltimore Avenue, 20705, Beltsville, MD, USA aut Barnaby J. Crop System and Global Change Laboratory, USDA-ARS, Building 001, Room 342, BARC-west, 10300 Baltimore Avenue, 20705, Beltsville, MD, USA aut Bailey B. Sustainable Perennial Crops Laboratory, USDA-ARS, Building 001, Room 245, BARC-west, 10300 Baltimore Avenue, 20705, Beltsville, MD, USA aut Photosynthetica The Institute of Experimental Biology of the Czech Academy of Sciences 53/1(2015-03-01), 3-10 0300-3604 53:1<3 2015 53 11099 https://doi.org/10.1007/s11099-015-0074-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11099-015-0074-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sicher R. Crop System and Global Change Laboratory, USDA-ARS, Building 001, Room 342, BARC-west, 10300 Baltimore Avenue, 20705, Beltsville, MD, USA aut NATIONALLICENCE 700 1- Bunce J. Crop System and Global Change Laboratory, USDA-ARS, Building 001, Room 342, BARC-west, 10300 Baltimore Avenue, 20705, Beltsville, MD, USA aut NATIONALLICENCE 700 1- Barnaby J. Crop System and Global Change Laboratory, USDA-ARS, Building 001, Room 342, BARC-west, 10300 Baltimore Avenue, 20705, Beltsville, MD, USA aut NATIONALLICENCE 700 1- Bailey B. Sustainable Perennial Crops Laboratory, USDA-ARS, Building 001, Room 245, BARC-west, 10300 Baltimore Avenue, 20705, Beltsville, MD, USA aut NATIONALLICENCE 773 0- Photosynthetica The Institute of Experimental Biology of the Czech Academy of Sciences 53/1(2015-03-01), 3-10 0300-3604 53:1<3 2015 53 11099