Abstract: The present invention is concerned with the improvement of aghcobiological traits in plants. More specifically, it relates to a plant cell comprising in its chloroplasts enzymatic activities for converting glycolate into malate. Preferably, said plant cell comprises a first polypeptide having glycolat oxidase activity, a second polypeptide having malate synthase activity and a third polypeptide having catalase activity or a first polypeptide having glycolat dehydrogenase activity and a second polypeptide having malate synthase activity. Also encompassed is a plant comprising said plant cells as well as seeds obtainable from the said plants. The present invention, furthermore, relates to a method for producing a transgenic plant or a plant cell having an increased water use efficiency or increased yield. The present invention contemplates polynucleotides comprising a combination of nucleic acids encoding the aforementioned polypeptides as well as vectors comprising the polynucleotides and uses thereof.