Topic
Shoot
About: Shoot is a research topic. Over the lifetime, 32188 publications have been published within this topic receiving 693348 citations.
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TL;DR: It is demonstrated that a single dominant gene could regulate a complex trait, root growth, and cytokinin regulates root growth in a largely organ-autonomous fashion that is consistent with its dual role as a hormone with both paracrine and long-distance activities.
Abstract: Optimizing root system architecture can overcome yield limitations in crop plants caused by water or nutrient shortages. Classic breeding approaches are difficult because the trait is governed by many genes and is difficult to score. We generated transgenic Arabidopsis thaliana and tobacco (Nicotiana tabacum) plants with enhanced root-specific degradation of the hormone cytokinin, a negative regulator of root growth. These transgenic plants form a larger root system, whereas growth and development of the shoot are similar. Elongation of the primary root, root branching, and root biomass formation were increased by up to 60% in transgenic lines, increasing the root-to-shoot ratio. We thus demonstrated that a single dominant gene could regulate a complex trait, root growth. Moreover, we showed that cytokinin regulates root growth in a largely organ-autonomous fashion that is consistent with its dual role as a hormone with both paracrine and long-distance activities. Transgenic plants had a higher survival rate after severe drought treatment. The accumulation of several elements, including S, P, Mn, Mg, Zn, as well as Cd from a contaminated soil, was significantly increased in shoots. Under conditions of sulfur or magnesium deficiency, leaf chlorophyll content was less affected in transgenic plants, demonstrating the physiological relevance of shoot element accumulation. Our approach might contribute to improve drought tolerance, nutrient efficiency, and nutrient content of crop plants.
432 citations
TL;DR: Tomato fruits ripened 95, 65, 46 and 42 d after flower opening when plants were grown under controlled environmental conditions at 14, 18, 22 and 26 °C, respectively, and were more sensitive to elevated temperature in their later stages of maturation.
431 citations
TL;DR: It is concluded that, for these annual species, root/shoot partitioning is partially consistent with optimal partitioning theory but that is also highly ontogenetically constrained.
Abstract: 1. We tested whether plants increase root :shoot ratios to compensate for limitations of below-ground resources in a manner consistent with optimal partitioning theory or whether the relative production of roots and shoots is controlled by species-specific developmental patterns. Individuals of two annual plant species, Abutilon theophrasti and Chenopodium album, were grown from seed in controlled greenhouse conditions under high- or low-nutrient regimes. Mid-way through the experiment, a sub-set of low-nutrient-grown plants were given high nutrient availability and a sub-set of high-nutrient-grown plants were transferred to a low nutrient environment. 2. Under continuous nutrient regimes : (1) high-nutrient-grown plants of both species grew faster and had a lower root :shoot ratio than low-nutrient-grown plants, consistent with optimal partitioning theory ; (2) both species exhibited a substantial amount of ontogenetic drift as root :shoot ratios decreased through ontogeny (subsequent to an initial increase in R/S shortly after germination) ; (3) allometric analyses revealed that increased allocation to roots occurred very early in ontogeny for both species, after which the relative growth of shoots exceeded that of roots in low-nutrient-grown plants compared to their high nutrient-grown counterparts - a result inconsistent with optimal partitioning theory. 3. Under temporally varying nutrient regimes : (1) growth substantially increased in low-nutrient-grown plants that were switched to a high-nutrient environment without a change in root :shoot partitioning ; (2) there was no change in growth or partitioning when plants were switched from a high- to a low-nutrient regime. 4. We conclude that, for these annual species, root/shoot partitioning is partially consistent with optimal partitioning theory but that is also highly ontogenetically constrained. This constraint is evident both in substantive ontogenetic drift in partitioning and in the period during development that plasticity in partitioning can be expressed.
427 citations
TL;DR: Special emphasis is given to data from laboratory experiments with small Betula pendula plants, in which the concept of steady-state nutrition has been applied, on the influence of mineral nutrient availability, light intensity and CO2 on growth and shoot:root ratio in young plants.
Abstract: The influence of mineral nutrient availability, light intensity and CO2 on growth and shoot:root ratio in young plants is reviewed. Special emphasis in this evaluation is given to data from laboratory experiments with small Betula pendula plants, in which the concept of steady-state nutrition has been applied.
425 citations
TL;DR: It is suggested that the reduction in shoot development and leaf elongation were related to toxic ion accumulation and depletion of K+ ions in the leaf blades and the accumulation of organic solutes in leaves did not appear to be related to salt tolerance.
422 citations