Root and shoot glucosinolates: a comparison of their diversity, function and interactions in natural and managed ecosystems

The role of glucosinolates in aboveground plant¿insect and plant¿pathogen interactions has been studied widely in both natural and managed ecosystems. Fewer studies have considered interactions between root glucosinolates and soil organisms. Similarly, data comparing local and systemic changes in glucosinolate levels after root- and shoot-induction are scarce. An analysis of 74 studies on constitutive root and shoot glucosinolates of 29 plant species showed that overall, roots have higher concentrations and a greater diversity of glucosinolates than shoots. Roots have significantly higher levels of the aromatic 2-phenylethyl glucosinolate, possibly related to the greater effectiveness and toxicity of its hydrolysis products in soil. In shoots, the most dominant indole glucosinolate is indol-3-ylglucosinolate, whereas roots are dominated by its methoxyderivatives. Indole glucosinolates were the most responsive after jasmonate or salicylate induction, but increases after jasmonate induction were most pronounced in the shoot. In general, root glucosinolate levels did not change as strongly as shoot levels. We postulate that roots may rely more on high constitutive levels of glucosinolates, due to the higher and constant pathogen pressure in soil communities. The differences in root and shoot glucosinolate patterns are further discussed in relation to the molecular regulation of glucosinolate biosynthesis, the within-tissue distribution of glucosinolates in the roots, and the use of glucosinolate-containing crops for biofumigation. Comparative studies of tissue-specific biosynthesis and regulation in relation to the biological interactions in aboveground and belowground environments are needed to advance investigations of the evolution and further utilization of glucosinolates in natural and managed ecosystems

Regeneration of Plantlets from various Explants of Tetraploid watermelon

Micropropagation of tetraploid watermelon is important to cope with high cost of seed. Seeds of tetraploid watermelon were grown in vitro to raise seedlings. Hypocotyl and cotyledonary explants and media supplemented with plant growth regulators (BAP and NAA) was explored for callus induction and organogenesis. Data was collected for callus, shoot and root induction. Maximum callus induction was observed at BAP 5 mgL-1 (76.66%) from cotyledon and (73.33%) from hypocotyls explant. The callus induced from different explants was sub-cultured on the shoot regeneration medium. Higher shoot induction (96.66%) was observed  from cotyledon and hypocotyl explant (76.66%) on MS + 1.0 mgL-1 BAP + 0.2 mgL-1 NAA with maximum number (6.3) of shoot per explant and average shoot length 4.5 cm. Among different types (NAA and IAA) and concentrations (0, 0.1, 0.3, 0.7, 1.0 mgL-1) of auxins investigated for root induction, maximum frequency of rooting was observed in 0.1 mgL-1 NAA while no root formation was observed at higher levels of auxin (1.0 mgL-1). Similarly in case of number of roots per shoot maximum root (4.3) was obtained on MS medium supplemented with 0.1 mgL-1 NAA. Key Words: Regeneration, Explant, Tetraploid, Water Mello

Effects of carbon source, carbon concentration and culture conditions on in vitro rooting of Pinus pinea L. microshoots

In stone pine (Pinus pinea L.), clonal propagation via adventitious shoot formation from cotyledons has been reported before but rooting of these shoots is poor. The number of rooted shoots had low frequency limiting the used of micropropagation protocols as a choice for mass propagation of superior genotypes. Therefore the main objective of the present work was to increase the number and quality of roots per shoot in order to ensure the survival and growth of a great number of plants in the acclimation phase. To achieve this, different combinations of carbon source (sucrose or glucose) at different concentrations, under different environmental conditions (temperature and light), were tested in the induction and expression phases of the adventitious root formation. Shoots of different clones obtained via organogenesis have been employed for the experiments. Observations were made on the rooting percentage, root length and number of roots per shoot. The results showed a general increased of the number of roots per shoot and an earlier root formation when glucose was used as a carbon source. However, there were no differences in the percentage of rooting between the carbons sources tested. The best results were obtained using 0.117 M of glucose and dark treatment combined with 19°C during the induction phase of the rhizogenic process. Light and low sugar concentration proved to be beneficial for the expression phase, increasing the root length. A remarkable interclonal difference in the ability to form roots was observed. It was possible to obtain a rooting percentage of more than 75% in several of the tested clones

Pattern formation during de novo assembly of the Arabidopsis shoot meristem

Most multicellular organisms have a capacity to regenerate tissue after wounding. Few, however, have the ability to regenerate an entire new body from adult tissue. Induction of new shoot meristems from cultured root explants is a widely used, but poorly understood, process in which apical plant tissues are regenerated from adult somatic tissue through the de novo formation of shoot meristems. We characterize early patterning during de novo development of the Arabidopsis shoot meristem using fluorescent reporters of known gene and protein activities required for shoot meristem development and maintenance. We find that a small number of progenitor cells initiate development of new shoot meristems through stereotypical stages of reporter expression and activity of CUP-SHAPED COTYLEDON 2 (CUC2), WUSCHEL (WUS), PIN-FORMED 1 (PIN1), SHOOT-MERISTEMLESS (STM), FILAMENTOUS FLOWER (FIL, also known as AFO), REVOLUTA (REV), ARABIDOPSIS THALIANA MERISTEM L1 LAYER (ATML1) and CLAVATA 3 (CLV3). Furthermore, we demonstrate a functional requirement for WUS activity during de novo shoot meristem initiation. We propose that de novo shoot meristem induction is an easily accessible system for the study of patterning and self-organization in the well-studied model organism Arabidopsis

IN VITRO MULTIPLE SHOOT INDUCTION FROM NODAL EXPLANTS OF CITRUS CULTIVARS

Citrus cultivars were explored for multiple shoot induction and root regeneration in different media. The multiple root and shoot induction was found directly proportionate to the increase in the levels of benzyleaminopurine (BA) and naphthalene acetic acid (NAA) in the modified Murashige and Skoog medium. The study might be promising towards in vitro propagation of sanitated Citrus plant material

Perbanyakan Tanaman Jambu Mete (Anacardium Occidentale L.) Melalui Jalur Organogenesis

Vegetativepropagation through in vitro culture has been carried out asa technology that has the potential for obtaining seedling insignificant amounts and relatively faster. This activity can bedone through the multiplication of adventitious shoots andlateral shoots (organogenesis). The goal of this research wasto find the method of cashew micropropagation throughorganogenesis. This study consisted of 4 main activities.They were shoot induction, shoot multiplication, shootelongation, and root induction. The results showed the bestmedium composition for shoot induction was MS + BA 0.7mg/l. The suitable media for shoots multliplication was MS +thidiazuron 0.5 mg/l + zeatin 1 mg/l and for shootselongation was MS + GA 1 mg/l + zeatin + 3 mg/l. The bestmethods for root induction was by submerging in vitroshoots in a solution of IAA 100 mg/l

Mikropropagasi Duku (Lancium Domesticum L., CV. Kalikajar) melalui Kultur Pucuk

The objectives of the research are to find out the influence of the mix between Kinetin and NAA and their best concentration level to result in the best effect on micropropagation of duku through shoot tip culture and to getting identic seedling of duku. The research was conducted in February to November 2007. It used randomized completely block design to constitute a three-repeated treatment. The treatment is made up by two factors. The first factor is the concentration of Kinetin consisting of three levels, those are 0 M (K0), 10-7 M (K7), and 10-6 M (K6). The second factor is the concentration of NAA, consisting of four levels, they are 0 M (N0), 10-7 M (N7), 10-6 M (N6) and 10-5 M (B5). The result of the study shows that the concentration combination of Kinetin and NAA has an influence to the shoot induction, this is number of shoots per eksplant, shoot multiplication I, those are number of leaves, shoot multiplication II, those are number of shoots per eksplant, number of leaves, buds length, shoot multiplication III, this is buds length, and root induction, those are number of roots and roots length. The best concentration combinations of Kinetin and NAA for shoot induction, shoot multiplication are K6N5, for root induction is K0N5. Those concentration combination respectively produce 3.05 shoots, 3.65 shoots, and 3,6 roots. Key words : kinetin, NAA, shoot tip, multiplicatio

Plant regeneration from seedling explants of common bean : Phaseolus vulgaris L.

For shoot induction and plant regeneration in bean we used MS media+BA and NAA. Multiple shoot induction was obtained in case of P. vulgaris cv. Fônix and Maxidor. The efficiency of regeneration from intact seedling (IS) and cotyledonary node (CN) explants was compared. The optimum treatment for the induction of multiple shoot formation was the culturing of (IS) on MS-based media+BA and NAA. Multiple shoot induction on dry bean (CN) cultured on full MS medium+1mg/l BA and 0.1mg/l NAA was feasible. Shoots that were 2cm in length or longer and having 2 trifoliate leaves were responsible for rooting ability, and root development. The method can be applied in transformation experiments

Perbanyakan In Vitro Bawang Putih (Allium Sativum Var. Tawangmangu) Melalui Kultur Tunas Kapital (Shoot Apex)

The purpose of this research was to get the best combination of NAA and BAP concentration that enhance the growth of shoots and the best IBA concentration to root inducing from shoot apex explants of garlic on semi-solid MS medium. Research used experimental method with single factor and 2 steps induction of research, those are shooting and rooting. For the steps of shoot induction, the treatment used 9 combinations concentration BAP and NAA (k), those were k1 (NAA 0,25 ppm + BAP 1 ppm), k2 (NAA 0,5 ppm + BAP 1 ppm), k3 (NAA 0,75 ppm + BAP 1 ppm), k4 (NAA 0,25 ppm + BAP 1,5 ppm), k5 (NAA 0,5 ppm + BAP 1,5 ppm), k6 (NAA 0,75 ppm + BAP 1,5 ppm), k7 (NAA 0,25 ppm + BAP 2 ppm), k8 (NAA 0,5 ppm + BAP 2 ppm) and k9 (NAA 0,75 ppm + BAP 2 ppm). While for root induction used 3 treatments, those were i1 (IBA 1 ppm), i2 (IBA 2 ppm) dan i3 (IBA 3 ppm). The fastest time of shoot’s growth was 4,66 days after planting that appeared on k7 treatment. The treatment of k4 was the best average of the number shoots and leaves (2,66 and 4). Treatment of k3 was the best average of the lenght shoots and leaves (7,33 and 8,03). In the step of root induction, i2 is fastest time for root inductions (10 day after root induction) and the best average of the number root (2,66). Furthermore, i1 treatment was the best average of the lenght root (0,47 cm).Keywords: Garlic, MS, Plant growth regulator, Shoot apex, Tissue cultur