Allah (SWT) ordained that plants, people and animals receive their food from what plants produce in their green factories.
These green factories are built up by the plant at the beginning of its growth and are called by botanists “Chloroplasts” which contain the chlorophyll, which the Qur’an calls “Al-Khadir” (green substance), where the plant utilizes the light energy and changes it into chemical energy leading ultimately to the production of various kinds of grain, fruit and other parts of vegetation that we see in gardens and fields.
The Qur’an draws our attention to these facts in the Saying of Allah (SWT):
“It is He who sends down water (rain) from the sky. With it We produce vegetation of all kinds from which (water or plants) We produce green substance (Khadir), out of which We produce grain in clusters. And out of date palms, from their spathes come forth clusters of dates hanging low and near, and (We produce) gardens of grapes, olives and pomegranates, each similar (in leaves or shape), yet different (in fruit and taste). Look at (and think over) their fruits when they begin to bear fruit, and (look at) the ripeness thereof. Behold! In these things there are Signs for people who believe.” (Quran 6: 99)
Thus, these green factories appear in the plant at the beginning of its growth. The plant is produced from its seed or part of its body by means of water. Allah (SWT) sends rain down from the sky to produce with it vegetation of all kinds, and from the plant He produces these green factories that produce the substances necessary to produce grain, fruit and all the other parts of the plant.
Yet this fact was not uncovered to people till 1600 AD, after 300 years of research, when botanists carried out numerous researches and experiments in the field of botanical physiology to understand the process of photosynthesis.
In 1804 AD, De Saussure proclaimed that there are two types of gas exchange: one type takes place in the light, the other in the dark, and that it is the green parts of the plant that absorb CO2 and release O2 in the presence of light. Then there proceeded continuous discoveries in this field.
In 1942 AD Meyer said that the original source of energy used by plants and animals is the sun and that the light energy absorbed by plants is converted into chemical energy through photosynthesis.
In 1961 AD Glass said that the most significant compounds involved in the process of converting the light energy into chemical energy in plants are the pigments found inside the chloroplasts or “pigment carriers”.http://www.quranandscience.com/featured-articles/340-al-khadir-the-holy-quran-on-chloroplasts