Interesting questions. No, it is not "GM." The submergence tolerant rice developed by IRRI (The International Rice Research Institute) is based on a trait first identified in "land race" rice cultivars first collected in the 1950s. The role of biotechnology is that modern gene sequencing technology (marker assisted breeding) was used to identify the "locus" or part of the rice genome so that it could be more efficiently bred into modern cultivars. The trait involves two or three genes but it was not moved into the modern cultivars with genetic engineering techniques which is what is often called "GMO." The process is described here: http://www.scribd.com/doc/52396969/Submergence-Tolerant-Rice-SUB1’s-Journey-from-Landrace-to-Modern-Cultivar?secret_password=1hgwimrg7y7hursw38yz
Drought tolerance and salinity tolerance are important traits that are being pursued in three ways. Traditional plant breeding has been making steady progress, particularly with regard to drought tolerance. Marker assisted breeding is accelerating that process. There has also been a great deal of basic research in academia and companies on transgenic approaches to these stress tolerance traits. It will probably take more time to understand which will have the greatest benefit under a range of real-world conditions.