What is the problem with dna that is bound to histones and compacted?

This is a problem mainly because process such as DNA replication, and protein synthesis are halted and cannot occur, thus the DNA needs to be in its loose chromatin form for the DNA Binding proteins to bind to specific regions to add base pairs and extend the DNA strand and or make a transcript to make proteins.

That is true tge cactus as a structural adaptation to its envirinment has it leaves reduced to spines. but this doesnt mean it cant produce food it produces food because of the presence of chlorophyll in its stem