Cross sections of corn roots (IMAGE) Penn State Caption Cross sections of corn roots showing genetic variation for aerenchyma formation, which converts living cells to air space. Now that researchers have found the gene associated with the phenotype, it can be a plant-breeding target. Credit Tania Galindo Castaneda/Penn State Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.