How are microtubules thought to affect cell shape in plants? microtubules of the plant cell cortex are thought to affect the movement of cellulose-synthesizing enzymes in the cell membrane, which, in turn, affect cell wall growth and shape. microtubules of the plant cell vacuole are thought to affect the movement of cellulose-synthesizing enzymes in the cell membrane, which, in turn, affect cell wall growth and shape. microtubules of the plant cell cortex are thought to affect the movement of lipid-synthesizing enzymes in the cell membrane, which, in turn, affect cell wall growth and shape. microtubules of the plant cell wall are thought to affect the movement of cellulose-synthesizing enzymes in the cell membrane, which, in turn, affect cell wall growth and shape. 5. microtubules of the plant cell nucleus are thought to affect the movement of cellulose-synthesizing enzymes in the cell membrane, which, in turn, affect cell wall growth and shape.