Expression of two Arabidopsis thaliana GARP-family transcription factors, AtGLK1, SEQ ID NO: 2, and AtGLK2, SEQ ID NO: 4, in tomato plants resulted in intensely green fruit that ripen to a normal red color. These Golden2-like (GLK) transcription factors were expressed under the control of several promoters in transgenic tomato lines. When AtGLK1 or AtGLK2 expression was regulated with the constitutive 35S promoter or with three promoters that enhanced expression in fruit tissues, the chlorophyll content of mature green fruit was increased by as much as 100%. The chloroplasts in green fruit expressing AtGLK1 or AtGLK2 developed earlier, were enlarged and had more extensive thylakoid granal development. In addition, expression of AtGLK1 or AtGLK2 resulted in increased starch accumulation in green fruit and higher levels of sugars in ripe fruit. In contrast to wild-type fruit, fruit expressing AtGLK1 developed full green color when they developed in the absence of light. Manipulation of the expression of GLK-like transcription factors in plants may provide a means for improving plant organ nutritional properties, particularly in plants or plant organs grown or maintained under low irradiance.