Central factor in ethylene signaling pathways that control development, senescence and grain size. Acts as positive component of the ethylene-signaling pathway. Expressed in roots, leaf sheaths, leaf blades, flowers, developing seeds, germinating seeds and young seedlings (PubMed:15047876). Expressed in adventitious roots, vascular tissues of the seminal roots, lateral roots, the connecting region between vascular tissues and lateral roots, mature leaf, mature stem, tips of adventitious roots derived from the node, shoot apex, young panicle, anthers, pistil, stigma, ovary, seed coat and fruit coat pericarp. Mutant etiolated seedlings display insensitivite ethylene-response in roots and coleoptiles. Mature mutant plants have reduced shoot length, increased number of panicles and reduced grain yield. Plants silencing EIN2 display a stunted phenotype with severe inhibition of shoot elongation and produce high levels of ethylene (PubMed:15047876). 'Mao huzi' means cat whiskers in Chinese (PubMed:23718947). Belongs to the NRAMP (TC 2.A.55) family.