外源多胺(精胺、亚精胺、腐胺)可增加苹果幼苗新根数量，但效果不及IBA；IBA能够促进多胺与核酸的积累，有效期20-27天;多胺亦可增加RNA，DNA的含量；处理和对照内源多胺与核酸含量均同步变化。

介绍了限根栽培措施和理论依据(地上地下的相关性、根系局部营养、生长冗余)、限根对植物生长发育的影响、限根的生理反应和作用机制以及限根技术的应用等间题。

The effect of plant growth substance and fertilizer on root formation was studied in new planted apple tree (Malus pumila Mill / Malus hupenensis Rhed). The results indicated that urea and IBA (Indolebutyric acid) and sheep dung all increased the total number and activity of new roots and changed the ratio of absorbing root to extensive root obviously. Urea increased the number of extensive root and decreased the ratio of root to shoot mostly. IBA lengthened the extensive root and increased the ratio of root to shoot obviously. Sheep dung increased the number of absorbing root and increased the ratio of absorbing root to extensive root, divided new root into mangy branches, increased the fresh weight of root and thicken extensive root. The fresh weight of root increased and the ratio of root to shoot declined after urea added to sheep dung. Both the ratio of absorbing root to extensive root and root fresh weight was increased after IBA added to sheep dung, then the ratio of root to shoot had no change obviously.

促分裂原活化蛋白激酶(mitogen-activated protein kinases, MAPKs) 是一类丝氨酸/ 苏氨酸(Ser/ Thr) 蛋白激酶，人们已在多种植物中发现大量MAPK家族成员。它们同动物和酵母MAPK类似,由MAPKs、MAPKKs (MAPK kinases) 、MAPKKKs (MAPKK kinases)等3 种类型的激酶构成一个MAPK级联途径(MAPK cascade)，在传递激素和环境胁迫等多种信号的过程中起作用。本文着重介绍了MAPK级联途径在植物病原物侵染、机械伤害等逆境信号传递过程中的作用。

L-精氨酸在植物中除作为一种重要的氮素贮藏营养物供再利用外，还是生成多胺和一氧化氮（NO）等的前体物质，而多胺和一氧化氮都是植物中重要的信使分子，参与包括生长发育、抗逆性等在内的几乎所有的生理生化过程。精氨酸脱羧酶（ADC）、精氨酸酶和一氧化氮合酶（NOS）是L-精氨酸分解代谢的关键酶，精氨酸可经ADC 或精氨酸酶-鸟氨酸脱羧酶（ODC）途径形成多胺，也可经NOS 途径形成NO，3 个酶活性的相对强弱，决定了精氨酸的代谢方向。根系在越冬期间会积累丰富的精氨酸；精氨酸代谢对于植物感知和适应环境变化有重要意义。