Unless exposed to light, roots are not green and lack plastids with their chlorophylls and carotenoid pigments. Similarly, the presence of anthocyanins in roots is uncommon although they do occur in roots of some species even in darkness.
Thank You, Constance Nozzolillo, What would be its significance in terms of phytochemicals? Does roots have something additional to what shoot do not have?
Secondary metabolites usually show some adaptation to the surrounding environment (drought, salinity, etc…) and participate in this adaptation. Root is in direct contact with soil and is the main organ absorbs water. In general, usually, there are differences in these metabolites and these organs' phytochemistry indeed.
Thanks, @Fatma Hamada. Could you exactly tell me what are the phytochemicals (functional groups) that are present in root but absent in shoot. And vice-verse.
This question cannot address any certain stuation that can be generalized for entire plant species you asked. Root and shoot system are connected but should be evaluated independently. Think about carrot. And its shoots, this might be a certain example that you asked for...
Not many studies have been made to answer this question, but both root and shoot contain the same genes and therefore have the potential to produce the same complement of phytochemicals. However, the different environments in which root and shoot exist will affect which genes will be "turned on" so it is not unreasonable to expect that there will be differences in the array of so-called "secondary" compounds. One of my students did a study with lentil seedlings and showed that each part of the plant, whether stem, leaf, flower or root, showed a different array of flavonoids in the thin-layer chromatograms she prepared from extracts.
@Buhara Yucesan, Very true, but still are there any phytochemical groups that are very distinct in roots but never in shoot and viceversa. Have much research gone to it? Or is there evidence of study to completely deny that this can never happen? I'm looking for scientific papers in these context.
@Constance Nozzolillo, exactly even if the genes are same and they are capable to produce the same complement of phytochemicals there would definitely influence on which to express and which not. I'm super glad to know the studies on lentil seedlings, is it published? can I get access to paper?
Meanwhile, it was interesting to note the phrase 'so called' and the inverted comma over "secondary" could you please elaborate on why you have done so?
In my young days long ago, plant physiologists regarded studies of plant constituents essential to life, i.e. "primary" compounds like amino acids, as most important and called things like flavonoids "secondary" compounds. Today, physiologists now recognize the importance of such compounds, especially in ecological interactions, so now they are referred to by the more prestigious name of "phytochemicals". How times have changed!
The results of the study of lentil seedlings was published only as a Master's thesis at the University of Ottawa. The results show differences in chromatographic mobility but do not identify specific compounds.
I do agree with Dr Constance Nozzolillo, that "both root and shoot contain the same genes and therefore have the potential to produce the same complement of phytochemicals". The difference is in quantities, some are dominant while others are peresent in few quantities.
Please see the up loaded scientific paper on my page (Macro, Micro-morphological and bioactivity aspects of naturalized exotic Solanum diphyllum L.), hope it could give small glimpse about what I want to say.
It depends on the species or stress conditions to the plant firstly. The geophyte plants includes more of phytochemicals in tubers. So the quantities are different in any body part of plant. I am not sure about the specific content in root that is not existed in shoot but if you write a specific plant i can help.