BWR (Boiling Water Resistant) Grade would be the best choice, as it is relatively inexpensive and will serves the purpose of being waterproof and durable if the cabinets are not too close to the steam sources or the water sources (sink) in the kitchen.
BWR Plywood ideally made of Type A bond (Phenol Formaldehyde bonded - extended) should be used. However 10% Melamine fortified Urea Formaldehyde Resin (MUF) can serve the same purpose . The 10% Melamine fortification in UF Resin ensure that the Plywood resists water soaking for atleast 8 hours which should be more than enough in normal well designed kitchen.
In cases, where there is chances of very high moisture for longer time periods consistently it would be wise to go for Marine Grade Plywood which is made to be 100% waterproof able to withstand 72 hours in boiling water. Marine Plywood is Type A bonded with Phenol Formaldehyde Glue. So it is the best of the best plywood available freely in market.
Last few decades have seen a lot of usage of plywood in various kitchen and modular kitchen designs. With lamination included, the look of plywood is enhanced to heights. Plywood also known as engineered wood is crafted, treated and factory-made using special panels of wood. Mostly made from wood veneers, this type of wood is extensively used in various kitchen designs. We BoardsIndia, also manufacture High Quality Laminated Plywood for Modular Kitchens.