The book has been especially edited for rational use by planners, scientists, investigators, academicians and postgraduate students. This book is an exceptional assimilation of timely, vital and inclusive twelve worthy reviews of varied significance, especially in view of the changing macro- and micro-climate influencing physiology of plants at all levels, contributed by true commitment of experienced, laudable and well-known scientists/ stalwarts all over the world. This is also strongly realized that there is with time more a need of united effort for the holistic development in the agricultural sciences, which absolutely depends on environmental situations. The threat of changing climate has imposed challenge to world scientists and their efforts in understanding reasons of yield reductions at physiological and molecular levels have been intensified. The consistent outcome are imparted with genetic engineers who have to now under the present circumstances exclusively identify, isolate and purify specific genes from DNA sequences befitting for development of tolerance mechanism in crop plants under changes of different degrees of intensity in environment. That is naturally the step wise long process having several pros and cons to arrive at any conclusion. Hence, the treatise series is the need of the hour and excellent source to disseminate meaningful distilled thoughts emerging out of extensive research which has due relevance for planning consequential basic strategic research besides direct help to the mankind. The intricacies of abiotic and biotic stresses on growth and development of plants have been understood in the last few decades. This book too is an endeavour to make aware the young workers to gain information on researches of basic and applied significance for extending consequential research of physiological and molecular approaches for crop improvement under changing environment. The manifold ideas on basic problems of the present and the future as well as resolutions, in part, have been consolidated which will be accomplished in subsequent volumes.