Response of tea plants (Camellia sinensis (L.) O. Kontze) to Al (300 lM AlCl 3 for 14 weeks) was studied in combination with deficient (-B) or adequate B supply (?B) in hydroponics. Aluminum improved plant growth under B deficiency. This positive Al effect in (-B) plants was related to an Al-induced increase of B contents in the root cell walls (CW). Moreover, in (-B) plants more Al was partitioned into CW-bound fractions in both leaves and roots than in (?B) plants; an indication that B deficiency reduced the mobility of Al in the tea plants. In general, the highest activities of phenylalanine ammonia lyase, polyphenol oxidase, and soluble and CW-bound fractions of peroxidases were observed in (?Al/-B) plants. In (-B) plants Al supply caused a reduction of CW-bound phenolic acids and lignin, while the concentrations of soluble phenolics increased in the leaves. In the roots, however, Al treatment of B-deficient plants caused a significant increase of CW-bound phenolic acids, but not of lignin. Our results suggest that increased B partitioning into CW and reduction of lignification were important causes for Al-mediated amelioration of growth in B-deficient plants. In addition, the observation that in (?Al/-B) roots CW binding of both Al and phenolic acids was enhanced indicates that in the B-deficient roots Al was mainly bound to the CW phenolic acids; this, in turn, reduced their availability for enzymatic reactions and lignin synthesis.

Interaction between aluminum (Al) and boron (B) in Al accumulator species has not been characterized so far. In this work, tea Camellia sinensis (L.) O. Kuntze plants were cultivated hydroponically and treated with adequate (control) or low B supply (-B) without or with 300 µM Al (-B+Al) for 14 weeks. Growth of B-deficient plants was completely resumed by Al supplementation or even surpassed control plants regarding shoot biomass. Net photosynthetic rate was negatively influenced by the low B supply, and the Al treatment increased it up to the level of the control plants that was reflected in the higher content of saccharides. The activity of ascorbate peroxidase (APX) in the younger leaves decreased at the low B supply accompanied with an increased H 2 O 2 content. The Al treatment increased the APX activity up to the level of the control plants simultaneously with the reduction of H 2 O 2 . Activities of superoxide dismutase (SOD) and peroxidase (POD) increased in the low B plants and the Al treatment augmented this effect. The content of malondialdehyde (MDA) in the leaves increased by low B but declined upon the Al treatment. In the Al-treated plants, the activity of nitrate reductase (NR) and the content of free α-amino acids exceeded those of the control plants, and nitrite concentration diminished. The shoot and root B content of the B-deficient plants supplemented with Al was similar with the B-sufficient ones. The results demonstrate that the up-regulation of C and N metabolism, the activation of antioxidative defense, and the enhancement of B uptake and transport were mechanisms for growth amelioration of the B-deficient plants by Al supplementation in tea.

The effects of boron (B) deficiency and water stress were studied in tea plants (Camellia sinensis [L.] O. Kuntze) grown in growth chambers in perlite irrigated with a nutrient solution. Dry matter production was reduced significantly by both low B supply and water stress. Shoot-root translocation of B declined in waterstressed plants. In addition, the re-translocation of B was impaired under drought, which was reflected in a significantly lower ratio of B content of young to old leaves in both B-deficient and B-sufficient plants. Leaf photochemical parameters were negatively influenced by B deficiency and water stress in the old but not in the young leaves. Although B-deficient plants were more conservative in relation to water loss following elevated stomatal limitation, their water potential was lower than in B-sufficient plants irrespective of the watering regime. Under the combined effects of B deficiency and water stress, the reduction in the CO 2 assimilation rate was more prominent than that under a single stress factor. The reduction of the net assimilation rate (A) in B-deficient plants due to water stress and in water-stressed plants due to low B supply were not accompanied by significant changes in the stomatal conductance, suggesting an involvement of non-stomatal factors. The activity of antioxidant enzymes and proline content increased under B deficiency and water stress conditions. Our results suggested that, in young leaves that have been developed under water stress, an acclimation to water stress conditions occurred that was well reflected in their more stable photochemistry, water relations and an efficient antioxidant defence system compared with the older leaves. Abbreviations:APX -ascorbate peroxidase, B -boron, Chl -chlorophyll, Φ PSII -effective quantum yield of PS II, F'v/F'm -excitation capture of open PS II, MDA -malondialdehyde, Fv/Fm -maximum quantum yield of PS II, A -net assimilation rate, E -net transpiration rate, qN -non-photochemical quenching, qP -photochemical quenching, POD -peroxidase, ROS -reactive oxygen species, g s -stomatal conductance, SOD -superoxide dismutase.

This study aims to assess the effect of different types of buds and the clones of rubber seedling growth in polybag. Implementation was carried out in the village Rejodadi, District Sembawa, Banyuasin, South Sumatra. This study was carried out from August 2015 through November 2015. This study used a randomized block design (RAK) to 6 (six) treatments and four (4) replicates. The treatments studied were K1: eye scales, K2: eyes rarely, K3: eyes shut (IRR 112), K4: eye scales, K5: eyes rarely, K6: eyes shut (clone PR 261). Variables observed that the speed of growth of shoots (day), shoot height (cm), stem diameter (mm), the number of the petiole (leaf), the number of roots (pieces), root length (cm), root dry weight (g), the percentage plant seeds of life (%). The results showed that treatment of type buds scales and IRR 112 gives the best result against 23.35 cm shoot height, the number of strands 10.38 root, root length of 20.50 cm, and root dry weight of 1.78 g.