cells Article Overexpression of an Agave Phosphoenolpyruvate Carboxylase Improves Plant Growth and Stress Tolerance Degao Liu 1,2,†, Rongbin Hu 1,† , Jin Zhang 1,2 , Hao-Bo Guo 3, Hua Cheng 1 , Linling Li 1, Anne M. Borland 1,4 , Hong Qin 3, Jin-Gui Chen 1,2, Wellington Muchero 1,2, Gerald A. Tuskan 1,2 and Xiaohan Yang 1,2,* 1 Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA;
[email protected] (D.L.);
[email protected] (R.H.);
[email protected] (J.Z.);
[email protected] (H.C.);
[email protected] (L.L.);
[email protected] (A.M.B.);
[email protected] (J.-G.C.);
[email protected] (W.M.);
[email protected] (G.A.T.) 2 The Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA 3 Department of Computer Science and Engineering, SimCenter, University of Tennessee Chattanooga, Chattanooga, TN 37403, USA;
[email protected] (H.-B.G.);
[email protected] (H.Q.) 4 School of Natural and Environmental Science, Newcastle University, Newcastle upon Tyne NE1 7RU, UK * Correspondence:
[email protected]; Tel.: +1-865-241-6895; Fax: +1-865-576-9939 † These authors contribute equally to this work. Abstract: It has been challenging to simultaneously improve photosynthesis and stress tolerance in plants. Crassulacean acid metabolism (CAM) is a CO2-concentrating mechanism that facilitates plant adaptation to water-limited environments. We hypothesized that the ectopic expression of a CAM- specific phosphoenolpyruvate carboxylase (PEPC), an enzyme that catalyzes primary CO2 fixation in Citation: Liu, D.; Hu, R.; Zhang, J.; CAM plants, would enhance both photosynthesis and abiotic stress tolerance.