Physiological and transcriptomic analyses of roots from Malus sieversii under drought stress oleh Da-li GENG, Li-yuan LU, Ming-jia YAN, Xiao-xia SHEN, Li-juan JIANG, Hai-yan LI, Li-ping WANG, Yan YAN, Ji-di XU, Cui-ying LI, Jian-tao YU, Feng-wang MA, Qing-mei GUAN