This research was supported by the National Key Basic Research Program of China,the National Natural Science Foundation of China (31130012) to L..L.,and the National Natural Science Foundation of China (30972329) to X.W
A key question in the secondary growth of trees is how differentiation of the vascular cambium cells is directed to concurrently form two different tissues: xylem or phloem, class III homeodomain-leucine zipper (HD-...