The Aluminum Activated Malate Transporter (ALMT) family members are anion channels that play important roles in organic acid transport, stress resistance, growth, development, fertilization and GABA responses. The rice malate permeable OsALMT7 influences panicle development and grain yield. A truncated OsALMT7 mutant caused a reduction in malate permeability panicle apical abortion1 (paab1), lacking of 2 (3) transmembrane helices still have the ability of mediating malate efflux. We further investigated the characteristic of the truncated channels and the activity contribution of these transmembrane helices with TEVC and single channel analysis in X. laevis oocytes, and found that OsALMT7 formed as a homodimer by co-expressing OsALMT7 and paab1 in oocytes and detecting the physical interaction between two OsALMT7, and between OsALMT7 and paab1 mutant protein. Further study proved that not just OsALMT7, mutants of TaALMT1 inhibit wild-type TaALMT1 channel, indicating that ALMTs might perform channel function as homodimers. Our discovery brings a light for ion channel structure and homomultimer regulation understanding for ALMT anion channels and potential for crop grain yield and stress response improvement in the context of the essential role of ALMTs in these plant processes.