Zeatin

About: Zeatin is a research topic. Over the lifetime, 2467 publications have been published within this topic receiving 64092 citations. The topic is also known as: Zeatin & (E/Z)-zeatin.

Relationship between phytohormones and genic male sterility induced by space flight in maize

Abstract: High performance liquid chromatography (HPLC) was adopted to analyze the content of endogenous hormones such as zeatin( ZT),gibberellin( GAs),auxin( IAA) and abscisic acid( ABA) in male fertile plants and male sterile plants of maize derived from sister-cross population,which was produced with male sterile mutant induced by space flight. Exogenous GAs treatment was applied to plants of sister-cross population of maize,and the fertility of the maize plant both in the exogenous GAs treatment plots and the control plot was investigated. The results showed that the fertility segregation ratios of sister-cross populations did not change with exogenous GAs treatment. At the seedling stage,only the differences of IAA and ABA contents in leaf between fertile and sterile plants were significant at the 0. 05 level,and the differences of ZT,GAs,IAA and ABA contents between sterile and fertile plants all were at 0. 05 or 0. 01 level significant,at the jointing stage. At the uninucleate microspore stage the differences of IAA and ABA contents in anther were significant at 0. 01 level,but at the binucleate pollen stage only the difference of ABA content was significant at 0. 01 level. During the four different developmental stages,the contents of ZT,GAs and IAA were higher in fertile plants than in sterile plants,but the content of ABA was lower in fertile plants than in sterile plants in the two different tissues. It was concluded that exogenous GAstreatment could not alter the fertility of maize plants,so this mutant did not belong to the GAs sensitive type. The changes of the hormone level or the hormones ratio might be related to the pollen abortion of the male sterile material used in this experiment,and it seems that ABA and IAA may have a closer relationship with the fertility expression of the material used in this experiment than ZT and GAs according to the significance tests.

In vitro propagation and improving accumulation of coumarin in Lycium barbarum, a rare plant in the flora of Egypt

Abstract: Abstract Background The conservation of natural populations of plants is very important for maintaining biological diversity. Lycium barbarum (goji berries) is classified as a very rare plant in the Egyptian flora. Goji berry is a fruit commonly known as ‘super-fruit,’ due to its beneficial constituents and medicinal properties. The aim of this study was to determine the influence of media formula added with various cytokinins on axillary bud induction of L. barbarum from shoot tip. An additional objective of this study was to investigate the effect of 2,4-D, TDZ, zeatin, IBA and NAA on growth and development of the plant through different stages. The present study also aims to improve coumarin accumulation as one of the most active constituents in the plant. Results Sterilized shoot tips of L. barbarum were cultured without growth regulators on different media formulas: Murashige and Skoog basal medium (MS medium), Gamborg’s medium (B5 medium) and Woody plant medium (WP medium). MS medium gave the best shoot induction. The maximum multiplication rate of shoots was recorded on MS medium supplemented with 225.24 µM 6-benzyl amino purine (BAP). The best callus induction rate from in vitro derived young leaves was obtained on MS medium with 552.60 µM thidiazuron (TDZ). At 176.20 µM TDZ, the maximum shoot proliferation ability was obtained through organogenesis from the callus. MS medium with 220.25 µM TDZ produced the highest number (15 buds) and forming rate (96%) of adventitious buds through direct organogenesis. On MS medium with 304.86 µM naphthalene acetic acid (NAA), 100% rooting was obtained. Almost 95% of the in vitro-generated plantlets were successfully acclimatized. Furthermore, suspension culture containing MS medium with 552.60 µM TDZ and cinnamic acid at a concentration of 763 μM increased coumarin synthesis (1.95-fold), compared to control. Conclusion The in vitro regeneration of plants via leaf-mediated shoot organogenesis protocol presented in this study is well suited for L. barbarum propagation and produced large quantities of identical planting materials for desert revegetation and pharmaceutical industries. A very effective indirect regeneration method via callus culture provides a potential for this ethnomedicinal plant to be improved by genetic transformation procedures, in addition to mass propagation of elite plants. The cell suspension culture medium with 763 µM cinnamic acid had the highest coumarin accumulation.

Physiological Comparison of Abscising Rudimentary Leaf and Vigorously Developing Panicle in Litchi: Antioxidant Enzymes and Phytohormones

Abstract: Floral bud of litchi (Litchi chinensis Sonn.) is a mixed bud consisting of leaf primordia, rudimentary leaves and panicle primordia. According to field observation, vigorous development of panicle results in abscission of rudimentary leaves. In this study, abscising rudimentary leaves (AL) and their subtending developing panicle (DP) were sampled from the terminal shoots of cvs. 'Nuomici' and 'Feizixiao'. In 'Nuomici', AL had a higher superoxide dismutase (SOD) activity compared to the DP. In 'Feizixiao', however, no significant difference was found between them, although AL had lower SOD activity. Peroxidase (POD) activity in AL was higher and ascorbate peroxidase (APX) was lower than that in DP, whereas H 2 O 2 concentration was higher in AL than in DP in both cultivars. The DP had higher levels of zeatin plus zeatin riboside (ZRs) and auxin (IAA) and lower levels of abscisic acid (ABA) than AL. The results suggested that different developmental fates of AL and DP had different antioxidant activities and hormone balance. High levels of SOD and APX activities and low levels of POD activity and H 2 O 2 concentration, together with high levels of ZRs, IAA and low level of ABA may be associated with the vigorous development of the panicle. Whereas low levels of SOD and APX activities, high levels of POD activity and H 2 O 2 concentration, low levels of ZRs, IAA and high level of ABA may be associated with the senescence and abscission of rudimentary leaves caused by panicle development.