Comparative analysis of the regulation of auxin-related genes in the stem base and root of four rice (Oryza sativa L.) cultivars with different root traits in response to tiller or root trimming

Rice is a staple food for greater than half of the world population. The root system is a vital part that affects the productivity of rice. Because of its presence underground and complexity, few investigations focused on the root system of rice. This study aims at following up the development of new roots and profiling the expression of auxin-related genes in the stem base and root of four rice cultivars. After trimming tillers or roots from the cultivars seedlings, the trimmed seedlings were left to regrow for five days until the new roots evolved in order to investigate shoot-root communication in relation to root development. The effect of tiller trimming was more pronounced on new root development than the effect of root trimming. Auxin-related genes were upregulated under tiller trimming compared to root trimming treatment, suggesting the redistribution of hormonal concentration to compensate for the minimized shoot sink. The study concluded that shoot-root communication affects the regulation of root development in rice.