As sessile organisms,the growth and productivity of land plants are continuously confronted with a variety of biotic and abiotic stresses.As a consequence,land plants have evolved a set of perception and signaling mechanisms to respond or adapt to adverse environmental conditions via regulation of transcription and gene expression,finetuning protein translation,modification and degradation,and metabolic reprogramming.Understanding the stress signaling pathways as well as the molecular and physiological mechanisms underlying stress tolerance in plants is not only fundamental for plant biology research,but also pivotal for practical applications such as genetic improvement of crops.Undoubtedly,the findings in the model species such as Arabidopsis thaliana and rice in the past two decades have greatly advanced our understanding on plant stress biology,whereas the distinct mechanisms by which certain crop and emerging model plants employ to survive under stresses are being extensively studied.In this context,Molecular Plant published a special issue on Plant Stress Biology (Volume 6,Number 2,2013),which has been freely accessible online since March 2014.