Mechanism of phytohormone involvement in feedback regulation of cotton leaf senescence induced by potassium deficiency.
Mechanism of phytohormone involvement in feedback regulation of cotton leaf senescence induced by potassium deficiency.
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植物激素参与缺钾棉花叶片衰老反馈调节机制
DOI：
10.1093/jxb/ers238
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发表时间：
2012-10
影响因子：
6.9
通讯作者：
Tian X
中科院分区：
文献类型：
--
作者：
Wang Y;Li B;Du M;Eneji AE;Wang B;Duan L;Li Z;Tian X
为了阐明缺钾诱导棉花叶片衰老反馈调节的激素基础，对缺钾敏感性不同的两个品种是自交和嫁接的下胚轴对下胚轴，在苗期采用标准嫁接（一个接穗嫁接到一个砧木上）、Y型嫁接（两个接穗嫁接到一个砧木上）和倒置Y型嫁接（一个接穗嫁接到两个砧木上）。缺钾（0.03mM的标准和Y嫁接，和0.01mM的倒置Y嫁接）增加了根脱落酸（阿坝）浓度的1.6- 3.1倍和木质部阿坝输送率的1.8- 4.6倍。缺钾还使木质部细胞分裂素[CK;包括玉米素核苷（ZR）和异戊烯基腺苷（iPA）类型]的递送速率降低29-65%，叶CK浓度降低16- 57%。在缺钾条件下，CCRI 41（对缺钾敏感）的叶片阿坝浓度和木质部阿坝释放量均高于SCRC 22（对缺钾不敏感），ZR和iPA型ABA水平均低于SCRC 22，表明棉花新梢影响叶片和木质部汁液中阿坝和CKs的水平。由于接穗对所有三种类型的嫁接根（砧木）和Y型和倒置Y型嫁接的砧木木质部汁液（收集在嫁接结合部下方）中的植物激素水平的影响很小，因此似乎参与木质部植物激素调节的向基反馈信号的位点是棉花幼苗的下胚轴。此外，这种反馈信号的目标更可能是下胚轴组织内木质部植物激素的变化，而不是植物激素从根的输出。
To elucidate the phytohormonal basis of the feedback regulation of leaf senescence induced by potassium (K) deficiency in cotton (Gossypium hirsutum L.), two cultivars contrasting in sensitivity to K deficiency were self- and reciprocally grafted hypocotyl-to-hypocotyl, using standard grafting (one scion grafted onto one rootstock), Y grafting (two scions grafted onto one rootstock), and inverted Y grafting (one scion grafted onto two rootstocks) at the seedling stage. K deficiency (0.03mM for standard and Y grafting, and 0.01mM for inverted Y grafting) increased the root abscisic acid (ABA) concentration by 1.6- to 3.1-fold and xylem ABA delivery rates by 1.8- to 4.6-fold. The K deficiency also decreased the delivery rates of xylem cytokinins [CKs; including the zeatin riboside (ZR) and isopentenyl adenosine (iPA) type] by 29–65% and leaf CK concentration by 16–57%. The leaf ABA concentration and xylem ABA deliveries were consistently greater in CCRI41 (more sensitive to K deficiency) than in SCRC22 (less sensitive to K deficiency) scions under K deficiency, and ZR- and iPA-type levels were consistently lower in the former than in the latter, irrespective of rootstock cultivar or grafting type, indicating that cotton shoot influences the levels of ABA and CKs in leaves and xylem sap. Because the scions had little influence on phytohormone levels in the roots (rootstocks) of all three types of grafts and rootstock xylem sap (collected below the graft union) of Y and inverted Y grafts, it appears that the site for basipetal feedback signal(s) involved in the regulation of xylem phytohormones is the hypocotyl of cotton seedlings. Also, the target of this feedback signal(s) is more likely to be the changes in xylem phytohormones within tissues of the hypocotyl rather than the export of phytohormones from the roots.
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影响因子：
3
作者：
Dodd, IC;Ngo, C;Beveridge, CA
通讯作者：
Beveridge, CA
影响因子：
7.2
作者：
Beveridge, CA;Murfet, IC;Rameau, C
通讯作者：
Rameau, C
影响因子：
6.9
作者：
Holbrook, NM;Shashidhar, VR;Munns, R
通讯作者：
Munns, R
影响因子：
6.9
作者：
Dodd, Ian C.;Egea, Gregorio;Davies, William J.
通讯作者：
Davies, William J.
影响因子：
56.9
作者：
GAN, SS;AMASINO, RM
通讯作者：
AMASINO, RM