Topic
Kinetin
About: Kinetin is a research topic. Over the lifetime, 7856 publications have been published within this topic receiving 135550 citations. The topic is also known as: Kinetin.
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TL;DR: A callus culture system of alfalfa has been developed which demonstrates the quantitative control of root and shoot organogenesis by growth regulators of the auxin and cytokinin type and enables the temporal separation of organogenetic induction from subsequent differentiation.
101 citations
TL;DR: The enhanced de novo biogenesis of withanolide A in shoot cultures was corroborated with radiolabel incorporation studies using [2-(14)C] acetate as a precursor and production of withaferin A was also found in the in vitro shoot cultures.
Abstract: Multiple shoot cultures of two experimental lines of Withania somnifera plants (RS-Selection-1 and RS-Selection-2) were established using nodal segments as explants. The hormonal combinations of benzyl adenine and kinetin not only influenced their morphogenetic response but also differentially modulated the level of biogeneration of withanolide A in the in vitro shoots of the two lines. Interestingly, withanolide-A, that was hardly detectable in the aerial parts of field-grown Withania somnifera (explant source), accumulated considerably in the in vitro shoot cultures of the plant. The productivity of withanolide A in the cultures varied considerably (ca. 10-fold, 0.014 to 0.14 mg per gram fresh weight) with the change in the hormone composition of the culture media as well as genotype used as source of the explant. The shoot culture of RS-Selection-1 raised at 1.00 ppm of BAP and 0.50 ppm of kinetin displayed the highest concentration of withanolide A in the green shoots of 0.238 g per 100 g dry weight tissue. This was a more analytical concentration keeping in view the isolation yields so far reported from the dried roots of the field-grown plant (ca. 0.015 g per 100 g dry weight), even if isolation losses are considered during purification. The enhanced de novo biogenesis of withanolide A in shoot cultures was corroborated with radiolabel incorporation studies using [2-14C] acetate as a precursor. Production of withaferin A was also found in the in vitro shoot cultures. As this compound is a predominant withanolide of native shoots as well and has been already reported to be accumulated in in vitro shoot cultures, its biogeneration observed in these shoot cultures is not discussed in detail.
101 citations
TL;DR: Foliar application of KIN and IAA counteracted some of the salt induced adverse effects by enhancing essential inorganic nutrients as well as by maintaining membrane permeability.
Abstract: This study examined the effects of kinetin (KIN) and indoleacetic acid (IAA) sprayed on the leaves of salinity- stressed maize (Zea mays L. cv., DK 647 F1) plants grown in field conditions. Salt stress was created by adding 100 mM NaCl to the irrigation water through a drip irrigation system during the irrigation schedule. Kinetin (KIN), indole acetic acid (IAA), and their combinations were sprayed foliarly. Salt stress (S) reduced the total dry matter, grain yield, chlorophyll content, and relative water content (RWC), but increased electrolyte leakage and proline accumulation in the maize plants. Foliar applications of both KIN and IAA treatments overcame to variable extents the adverse effects of NaCl stress on the earlier mentioned physiological parameters. However, the combination of KIN plus IAA did not improve salinity tolerance in maize plants. Salt stress increased Na + concentration, and reduced those of Ca 2+ and K + in the leaves of maize plants. Foliar application of both KIN and IAA significantly reduced Na + concentration and increased those of Ca 2+ and K + . Foliar application of KIN and IAA, especially at 2 mM, counteracted some of the salt induced adverse effects by enhancing essential inorganic nutrients as well as by maintaining membrane permeability.
101 citations
TL;DR: This experiment suggests that glucose and fructose may play important roles during salt stress because there were clearly higher concentrations of these sugars in the grain of the stressed cultivars under IAA and KIN application: it appears that their accumulation was the earliest response detected during the grain-filling period in rice.
Abstract: Phytohormones, such as auxin and cytokinin, are known to be involved in the regulation of plant responses to salinity stress and counteract the adverse effect of stress conditions. This work investigated the effects of the exogenous spraying of indole-3-acetic acid (IAA) and kinetin (KIN) during the reproductive phase on grain yield by examining the 1000-grain weight and filled-grain percentage as well as the changes in starch, total soluble sugars, sucrose, glucose and fructose concentrations in the grains of two rice cultivars under salt stress. The results indicated that the applied IAA and KIN led to an increased grain yield, 1000-grain weight and filled-grain percentage for both rice cultivars under salt stress. The storage starch content in the grain of the salt-sensitive cultivar was more than that in the salt-tolerant cultivar under IAA application compared with KIN, whereas a decrease in the total soluble sugar content was observed with both IAA and KIN treatments, in comparison to the non-hormone treatment. Interestingly, this study showed that IAA led to a much higher increase in the sucrose content in grain, as compared to the KIN. Furthermore, this experiment suggests that glucose and fructose may play important roles during salt stress because there were clearly higher concentrations of these sugars in the grain of the stressed cultivars under IAA and KIN application: it appears that their accumulation was the earliest response detected during the grain-filling period in rice. Finally, this work indicated that an increase in the rice grain yield, 1000-grain weight and filled-grain percentage are associated with an increase in the contents of starch, sucrose, glucose and fructose in grain caused by the application of IAA and KIN.
101 citations
TL;DR: Using this efficient regeneration system, plantlets were regenerated from seven elite maize inbred lines and provided a solid basis for genetic transformation of maize.
Abstract: An efficient maize regeneration system was developed using mature embryos. Embryos were removed from surface-sterilized mature seeds and sliced into halves. They were used as explants to initiate callus on induction medium supplemented with 4.0 mg l(-1) 2,4-dichlorophenoxyacetic acid (2,4-D). The induction frequency of primary calli was over 90% for all inbred lines tested. The primary calli were then transferred onto subculture medium supplemented with 2.0 mg l(-1) 2,4-D. Following two biweekly subcultures, embryogenic calli were formed. Inclusion of a low concentration (0.2 mg l(-1)) of 6-benzylaminopurine (BA) in the subculture medium significantly promoted the formation of embryogenic callus. The addition of silver nitrate (10 mg l(-1)) also supported an increased frequency of embryogenesis. The embryogenic callus readily formed plantlets on regeneration medium supplemented with 0.5 mg l(-1) BA. The regenerated plantlets were transferred to half-strength Murashige and Skoog medium supplemented with 0.6 mg l(-1) indole-3-butyric acid to develop healthy roots. The regenerated plantlets were successful on transfer to soil and set seed. Using this system, plantlets were regenerated from seven elite maize inbred lines. The frequency of forming green shoots ranged from 19.8% to 32.4%. This efficient regeneration system provides a solid basis for genetic transformation of maize.
101 citations