I want to design a plant-like organism that floats ~50km above the surface of Venus, where the conditions are somewhat Earth-like. I envision it to be a large photosynthesizing balloon on a very long tether to the planet surface, so that it has a method of obtaining nutrients: Drawing not to scale
My primary concern is with the tether, because not only would this tether have to be very long and be able to transport nutrients to the balloon at the top, it would have to withstand temperatures of 880 degrees Fahrenheit as well as 190-mph winds.
Putting aside the question of how such an organism would not be roasted by the Sun because of Venus' slow day/night cycle, is this feasible? If so, what sort of material would it be constructed of, and what kind of biochemistry could it have? If not, how could I modify the design so that such a plant is possible?