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。

The early-response of roots to water loss and the signal transduction of water loss to abscisic acid (ABA) biosynthesis were studied by polyethylene glycol (PEG 6000) treatments to apple rootstock (Malus hupenensis Reld) seedlings. The results show that the ABA content, the H2O2 production rate, the lipoxygenase (LOX) activity and the protein kinase (PK) activity all increase during water loss (30% PEG treatment) in apple roots. H2O2 content reaches a peak at 30～40 min, then drops and rises again at 180 min following treatment. Increase of H2O2 is the earliest and of ABA content is the latest among these events. The absorbance of H2O2 and inhibition of LOX reduce the ABA accumulation during water loss. Both exogenous H2O2 and soybean LOX are able to increase ABA content. The Ca2+ chelater (EGTA) and the inhibitor of PK and LOX all reduce the increment of ABA after water loss. The activity of LOX and PK increases after treatment by 1 mmol/L H2O2 in intact roots and a PK inhibitor reduces the increase of LOX activity by PEG and H2O2. The PEG treatment-induced increases of H2O2 content, PK and LOX activity all decrease after EGTA pretreatment. It suggests that the Ca2+, protein phosphorylation, active oxygen species and LOX are all involved in the ABA biosynthesis induced by water loss; the change of cytosol Ca2+ and H2O2 is the earliest event and LOX may be a key enzyme in some conditions. The pathway of the signaling cascade associated with water loss and ABA may be: PEG treatment → loss of cell water → loss of cell turgor → mechanical process → Ca2+ → H2O2 → PK → LOX → ABA accumulation.

本文综述了多胺与果树萌发、座果、果实发育、根系形成、花芽分化、果榭衰老的关系，以及多胺胁迫、多胺与激紊的关系和多胺的吸收运转特性。

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.

植物对水分胁迫信号作出反应，需要经过信号的识别、转导和胞间信使传递等过程。该文从胁迫感受、第二信使系统及蛋白质可逆磷酸化等方面，介绍了植物细胞对水分胁迫(原初) 信号和胁迫信号分子(脱落酸) 识别转导的研究进展。