NOVELTY - A polynucleotide encoding a modified oleosin including at least one artificially introduced cysteine, is new.    USE - The polynucleotide is used in genetic construct, or expression construct for producing plant which is used in biofuel feedstock and animal feed (all claimed).    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) genetic construct, or expression construct, comprising the polynucleotide;    (2) host cell comprising a polynucleotide;    (3) plant comprising a plant cell;    (4) modified oleosin including at least one artificially introduced cysteine;    (5) fusion protein comprising the modified oleosin fused to protein of interest;    (6) oil component comprising the modified oleosin;    (7) emulsion comprising a modified oleosin or oil component;    (8) composition comprising the modified oleosin or oil component;    (9) plant, or its portion comprising the oil component;    (10) animal feed comprising the oil component, or plant, or its portion or its tissue;    (11) method (M1) for producing an oil component, involves using (a) (i) at least two of modified oleosins, (ii) triacylglycerol, and (iii) phospholipids or (b)cultivating a host cell in conditions conducive to the production of oil;    (12) method (M2) for producing an oil component in host cell, involves (a) (i) introducing into a host cell at least one polynucleotide and (ii) culturing the host cell in order to express the modified oleosin or (b) (i) introducing into a host cell at least one polynucleotide and a nucleic acid molecule encoding a triacylglycerol (TAG) synthesising enzyme and (ii) culturing the host cell in order to express the modified oleosin and the TAG synthesizing enzyme;    (13) method (M3) for producing a photosynthetic cell with an increased rate of carbon dioxide assimilation, involves transforming the photosynthetic cell with a polynucleotide encoding a modified oleosin including at least one artificially introduced cysteine;    (14) non-photosynthetic tissue/organ of a plant produced by a method (M3);    (15) animal feed comprising the non-photosynthetic tissue/organ;    (16) biofuel feedstock comprising the non-photosynthetic tissue/organ; and    (17) method (M4) for producing oil, involves (a) providing a plant comprising a polynucleotide, and (b) cultivating the plant to express the modified oleosin and produce oil in its non-photosynthetic tissues/organs.