Growth Of Leaf Blades Research Articles

Effect of Waste Cooking Oil-Based Composite Materials on Radish Growth and Biochemical Responses

Waste cooking oil poses a serious threat to human health and the environment, both in households and in larger communities. One of the applications of waste cooking oil is composite materials called vegeblocks, which can be used for construction purposes. These composites are formed by the process of polymerisation, esterification and polyesterification. The resulting materials exhibit mechanical strength in line with the requirements for paving blocks. Composite materials that have been annealed for a minimum of 20 h at 200 °C or higher have the highest tensile strength (above 5 MPa). In contrast, composites with the highest flexural strength were obtained after processing at 210 °C for 16 h. The Saxa 2 variety showed the greatest inhibition of storage root growth (almost 43% compared to the control sample), as well as stimulation of root and leaf blade growth (by a maximum of 61.5% and 53.5%, respectively, compared to the control sample). The composite obtained from the maximum process parameters resulted in significant growth of both the root and the green part of both radish varieties by up to 35%. The study showed that the presence of vegeblocks in the plants causes stress conditions, resulting in increased peroxidase content compared to the control sample. The presence of the oil composite in the soil did not increase the amount of catalase in the radish, and even a reduction was observed compared to the control sample.

Leaf Blade Growth and Development in Red, Pink, and Yellow Petiole Cultivars of the Swiss Chards Grown in Floating Culture System

Leaf Blade Growth and Development in Red, Pink, and Yellow Petiole Cultivars of the Swiss Chards Grown in Floating Culture System

Potensi Bungkil Inti Sawit Sebagai Campuran Media Tanam Pada Tanaman Tomat (Lycopersicum Escalantum Mill)

Palm kernel meal or often referred to as (BIS) is one of the byproducts of processed palm oil in the manufacture of palm oil. The content of palm kernel cake (BIS) has fiber similar to the content in grass. Among other things containing less than 10% water, 14-17% protein, 9.5-10.5% fat and crude fiber 12-18%. Nutrition factions are cellulose, fat, protein, arabinoxilan, glucoronoxilan, and minerals. This material can be obtained by chemical processes or by mechanical means. So far, palm kernel cake (BIS) is widely used as animal feed because of the high protein contained therein, so it is very rarely used as a planting medium. This study aims to find the right composition in a mixture of palm kernel cake (BIS) which is good as a medium for planting a mixture of palm kernel cake (BIS) with mineral soil. In this study, the tomato nucleus (BIS) mixed tomato planting media had 4 treatments namely A0: without giving palm kernel cake (BIS), A1: 40 g palm kernel cake (BIS), A2: 50 g palm kernel cake (BIS), A3: 60 g palm kernel cake (BIS). The parameters measured were plant height growth and leaf blade growth based on the results of the study obtained, palm kernel cake has the potential to be one of the ingredients in making planting media.
 Keywords: Palm kernel cake (BIS), land application, tomato.

Genome-wide transcriptome analysis reveals molecular pathways involved in leafy head formation of Chinese cabbage (Brassica rapa)

Chinese cabbage plants go through seedling and rosette stages before forming their leafy head. Chinese cabbage plants resemble pak-choi plants at their seedling stage, but in their rosette stage the leaves of Chinese cabbage differentiate, as they increase in size with shorter petioles. In order to understand the molecular pathways that play a role in leafy head formation, transcript abundance of young emerging leaves was profiled during development of two Chinese cabbage genotypes and a single pak-choi genotype. The two Chinese cabbages differed in many aspects, among others earliness, leaf size and shape, leaf numbers, and leafy head shape. Genome-wide transcriptome analysis clearly separated the seedling stages of all three genotypes together with the later stages from pak-choi, from the later developmental stages of both Chinese cabbages (rosette, folding, and heading). Weighted correlation network analysis and hierarchical clustering using Euclidean distances resulted in gene clusters with transcript abundance patterns distinguishing the two Chinese cabbages from pak-choi. Three clusters included genes with transcript abundance affected by both genotype and developmental stage, whereas two clusters showed only genotype effects. This included a genotype by developmental stage cluster highly enriched with the MapMan category photosynthesis, with high expression during rosette and folding in Chinese cabbages and low expression in the heading inner leaves that are not exposed to light. The other clusters contained many genes in the MapMan categories Cell, showing again differences between pak-choi and both Chinese cabbages. We discuss how this relates to the differences in leaf blade growth between Chinese cabbage and pak-choi, especially at the rosette stage. Overall, comparison of the transcriptome between leaves of two very different Chinese cabbages with pak-choi during plant development allowed the identification of specific gene categories associated with leafy head formation.

Crop growth and development dynamics of two fodder beet (Beta vulgaris L.) cultivars sown on different dates in New Zealand

ABSTRACT Two fodder beet (Beta vulgaris L.) cultivars (‘Rivage’ and SF Brigadier™) were evaluated in a field experiment to quantify the effect of cultivar and sowing date on growth physiology. The crops were sown on 19 September, 17 October, 17 November and 15 December in 2014. Crops were sequentially harvested and separated into storage root, leaf blade and petiole for analysis. Fodder beet growth was sigmoidal; the growth of leaf blades and petioles dominated the lag phase while storage root growth dominated the exponential phase. The appearance of the 25th leaf marked the beginning of the exponential phase. The maximum growth rate was not affected by the cultivar or sowing date. Total dry matter (DM) yield was the same for September- and October-sown crops (2444 ± 164 g DM m−2); showing little advantage of early sowing because cold temperatures slowed canopy development. The November- and December-sown crops produced 18% and 30% lower yield than the October-sown crops. ‘Rivage’ partitioned 5% greater DM to the storage root, an indication of greater sink strength, than SF Brigadier. Information on the pattern of growth can aid management decisions for optimising yield, and is valuable for the improvement of fodder beet models.

Оцінювання впливу промислових умов на величину флуктуючої асиметрії листкової пластинки Betula Pendula Запоріжжя

Досліджено мінливість морфометричних параметрів листкової пластинки Betula pendula в різних насадженнях за впливом урботехногенного середовища м. Запоріжжя. Збір матеріалу проведено після зупинки росту листкових пластинок, наприкінці липня – на початку серпня 2017–2018 рр. Проби листків Betula pendula відібрано в зелених насадженнях санітарних зон 7 промислових підприємств з різними класами шкідливості. Вимірювання проведено за п'ятьма показниками у міліметрах (параметри 1–4) та градусами (параметр 5) з лівого і правого боків листкової пластинки. Під час аналізу комплексу морфометричних ознак використано інтегральний показник за методикою В. М. Захарова (2000). Найчутливішими до впливу урботехногенного середовища пластинки Betula pendula є показник 3 параметра – відстань між основами першої та другої жилок другого порядку, середнє значення якого становить 0,111 см. Параметр 2 – довжина другої від основи листка жилки другого порядку, є найбільш стійкий до впливу чинників техногенного забруднення середовища, асиметрія не перевищує 0,030 см. На основі обчислення середнього значення флуктуючої асиметрії встановлено залежність порушення рівня симетрії за дії забруднення довкілля. Мінімальне значення коефіцієнта асиметрії (0,040) зафіксовано в насадженнях Трансформаторного заводу. Найбільшого техногенного пресу Betula pendula зазнає в захисних насадженнях, що ростуть біля промислових об'єктів Вогнетриву, Запоріжсталь, Коксохіму, Дніпроспецсталь, Титано-магнівого та Алюмінієвого комбінатів (межі коливання показника флуктуючої асиметрії на цих ділянках від 0,058 до 0,065).

Biomass flow and defoliation pattern in alexandergrass fertilized with nitrogen

The determination of biomass flows can assist on improving pasture fertilization techniques, contributing to identify the best management methods and, in relation the use of fertilizers. Nitrogen deficiency in pastures can reduce forage production. On the other hand, there is an environmental concern on nitrogen (N) losses when this nutrient is used in excess and this concern guides the search for new grazing systems that optimize its use. Leaf biomass flow, intensity and frequency of defoliation were evaluated in Alexandergrass ( Urochloa plantaginea (Link) Hitch) fertilized with Zero, 100, 200 or 300 kg/hanitrogen (N) as urea. The grazing method was put and take stocking in order to keep the forage mass at 3,000 kg/haDM. The experimental animals were Angus heifers with an initial age of 15 months and body weight of 241.5±5 kg. The experimental design was completely randomized following a repeated measure arrangement, with four treatments and variable number of experimental units. The highest growth of leaf blades was achieved with 100 kg/haN. Senescence and intake flows and defoliation intensity were similar among the N levels used. The frequency of return to the same tiller (days) was influenced by N levels and evaluation periods. Our findings recommend the use of 100 kg/ha N in Alexandergrass pasture.

ВПЛИВ АБІОТИЧНИХ ЧИННИКІВ НА МОРФО-ФІЗІОЛОГІЧНІ ОСОБЛИВОСТІ РОСТУ ТА РОЗВИТКУ РОСЛИН НА ФОНІ ПРОТЕКТОРНОЇ ДІЇ ПРОДУКТІВ ВЕРМІКУЛЬТУРИ

<p>The effect of <em>MgSO<sub>4</sub></em> on morphometric specifics of the <em>Salix alba</em> L., which characterized by high rates of growth and development is investigated. Mg<sup>2+ </sup>was added in the form of <em>MgSO<sub>4*</sub>3H<sub>2</sub>O</em> at a concentration of 2.5 g/l considering of salt water content in the research solutions with <em>S. alba</em> L. and combined with plant growth regulator (GR) of natural origin Humisol. These studies have shown toxicity of<em>MgSO<sub>4</sub></em> at a concentration of 2.5 g/l during all the period of growth and development. So, <em>MgSO<sub>4</sub></em> had toxic effect on plant growth and development within whole period of observation. We registered negative correlation (R = - 0.99) between toxic properties of salt and the age of the studied plants (for example, the growth rate of shoots and leaf blades by <em>S. alba</em> L.) and positive correlation (R = 0.99) while studied the root growth rate, which was caused by the direct contact of rhizosphere and negative stressors.</p><p>The GR Humisol accelerated the rate of physiological processes of growth and development of shoots and roots in 2-3 times, but the growth of leaf blade was not activated regards the control. The combined effect of magnesium salts and GR levelled toxic concentrations of magnesium sulphate were accelerated plant growth or stimulated growth up to control values, promoted adaptation mechanisms of plants and provided a protective role against excessive salinity. We suggested using the Humisol as a natural product, vermiculture, adaptogene, protector, and fertilizer agent of natural origin, which provides for biota to consume the environmental services without damage to the environment under conditions of excessive pressure of salt stress on plant organism.</p>

Spatiotemporal Phytochrome Signaling during Photomorphogenesis: From Physiology to Molecular Mechanisms and Back.

Light exposure results in distinct responses in specific seedling tissues during photomorphogenesis. Light promotes growth of cotyledons and leaves, as well as development and elongation of roots, whereas light inhibits elongation of hypocotyls. For distinct plant responses such as shade avoidance, far-red light or shifts in spectral light quality similarly have disparate impacts on distinct plant tissues, resulting in elongation of stems or petioles and a reduction in growth of leaf blades for many species. The physiological bases of such tissue- and organ-specific light responses were initially studied using localized irradiation of specific tissues and organs, or irradiation of dissected plant parts. These historical approaches were used to identify spatial-specific pools of photoreceptors responsible for regulating local, i.e., tissue- or organ-specific, or distal, i.e., interorgan, plant responses. The red/far-red responsive phytochromes have been the most widely studied among photoreceptors in this regard. Whereas, the spatial localization of photoreceptors regulating many tissue- or organ-specific light responses were identified, the underlying signaling networks responsible for mediating the observed responses have not been well defined. Recent approaches used to investigate the molecular bases of spatiotemporal light responses include selective irradiation of plants harboring mutations in specific photoreceptors, tissue-specific expression of photoreceptors, primarily in photoreceptor mutant backgrounds, or tissue-specific biochemical ablation of photoreceptor accumulation. Progressive integration of such approaches for regulating the availability of localized pools of phytochromes with the use of transcriptomic or proteomic analyses for assessing the genes or proteins which these spatially discrete pools of phytochrome regulate is yielding emergent insight into the molecular bases of spatiotemporal phytochrome signaling pathways responsible for regulating spatiotemporal light responses of which we have been aware of at the physiological level for decades. Here, I discuss historical and emerging approaches to elucidating spatiotemporal signaling mediated by phytochromes during photomorphogenesis.

МОРФО-ФІЗІОЛОГІЧНІ ОСОБЛИВОСTІ РОСТУ ТА РОЗВИТКУ РОСЛИН В УМОВАХ ПІДВИЩЕНОЇ МІНЕРАЛІЗАЦІЇ

<p>The effect of increasing salinity to the morpho-metric parameters of Salix alba L., which dominated in the coastal areas on rivers of Steppe Dnieper, is investigated. We added Mg as salt MgSO<sub>4</sub> * 3H<sub>2</sub>O in the range of concentration: 0.5, 1.0, 1.5, 2.0 and 2.5 g/l in a solution of willow cuttings. In the solution was added and plant growth regulator "Kornevin" the synthetic origin. The negative effect of salt at a concentration from 1.0 g/l to 2.5 g/l in the dynamics of growth and development was found. The correlation between the size and salinity in dynamics of growth and development of plant were demonstrated: in the growth of shoots (R = 0.83, 0.91 and 0.95), in the growth of roots (R = 0.92, 0.68 and 0.84) respectively depended from salt concentration. The length of the leaf blade was from 4% to 8%, from 7% to 43%, from 333% to 11% (R = 0,68, 0,93, 0,61), depending on the concentration of salt and during observing compared with control (distilled water). "Kornevin" and combined effect of salt increased the length of the leaf blade growth by 4-5, 2-4, 3-5 times, the roots by7 and 3-14 times, the shoots by 3-4, 6-7 and 5-7 times in the dynamics of growth compared with control (MgSO<sub>4</sub>, 2,5 g/l).</p> <p>The recommendations regarding for the advisability of using the plant growth regulator "Kornevin", as very effective plant growth preparation that promoted rooting and activated physiological processes of plant organism, expressed protective effect in conditions of excessive salinity, were provided.</p> <p class="Style1"><em>Key words</em><em>:</em><em> </em><em>the morpho-metric index, the plant growth regulators, abiotic factors, salinity factor, the adaptation.</em><em></em></p>

A computational model of the effect of symplastic growth on cell mechanics in a linear leaf blade

The epidermis of a linear leaf, as in Poaceae, is established by parallel files of cells originating from the leaf base. Their feature is symplastic growth where neighboring cell walls adhere and do not slide along each other. We developed a simple mechanical cell-based model for symplastic growth of linear leaf blade. The challenge is to determine what restrictions on cell size symplastic growth creates compared to the free growing cells. We assume an unidirectional growing cell ensemble starting from a meristem-like layer of generative cells and then generating parallel cell rows from every cell of the initial layer. Each cell is characterized by its growth function, and growth of the whole leaf blade is accompanied by mutual adjustment between all the cells. Cells divide once they have reached a threshold area. A mathematical model and its implementation are proposed for computational simulation of 1D symplastic growth of tissues. The question analyzed is how a cell grows in a plant tissue if there is a mechanism for regulating the growth of an isolated growing cell and the behavior of the cell wall matter is elastoplastic. The results of the simulation of linear leaf blade growth are compared to those for a free-growing cell population.

MaizeAUXIN-BINDING PROTEIN 1andAUXIN-BINDING PROTEIN 4impact on leaf growth, elongation, and seedling responsiveness to auxin and light

In maize, at least five auxin-binding proteins (ABPs) have been identified, yet their functions remain unclear. The present study reports the use of maize abp1, abp4, and abp1abp4 mutants to investigate the role of ABPs during maize growth and development. Single and double abp mutant plants grown in a greenhouse differ from the wild type (WT) in their leaf declination and leaf blade growth. The effect of the dark (D), blue light (BL), red light (RL), and exogenous auxin on the development of mutant seedlings was also studied. Relative to WT, etiolated mutant seedlings were shorter and showed a reduced responsiveness to exogenous auxin. In BL or RL, the responsiveness of maize seedlings to auxin was distinctly less than in D. The reducing effect of light on seedling responsiveness to auxin is mediated at least by phytochromes. The suppression of ABP1 and (or) ABP4 led to a distinct accumulation of free indole-3-acetic acid (IAA) in etiolated and light-grown seedling organs. We concluded that ABP1 and ABP4 participate in the growth of maize seedlings, mediate seedling responses to auxin, and interact with light signaling pathway(s). We also deduce a functional interaction between ABP1 and ABP4, which is that the relationship between them is light-, organ- and response-dependent.

Características morfogênicas de milheto sob lotação rotacionada com diferentes períodos de descanso

O experimento foi realizado para avaliar as características morfogênicas de milheto (Pennisetum glaucum (L.) R.Br.) sob lotação rotacionada com três períodos de descanso, correspondentes aos tempo necessário para expansão de 1,5 a 2 folhas; de 2,5 a 3 folhas; e de 3,5 a 4 folhas. As características morfogênicas avaliadas em quatro repetições de área (piquetes) foram alongamento de lâminas foliares, senescência de lâminas foliares, alongamento de colmos, aparecimento de folhas, filocrono e duração de vida das folhas. As taxas de alongamento foram de 6,4; 5,8 e 5,3 cm/dia; as taxas de senescência de lâminas foliares, de 0,71; 0,82 e 1,19 cm/dia; as taxas de alongamento de colmo 0,73; 1,42 e 2,2 cm/dia; as taxas de aparecimento de folhas de 0,158; 0,119 e 0,118; e o filocrono, de 93; 118 e 128 graus-dia para os períodos de descanso de 1,5 a 2; de 2,5 a 3; e de 3,5 a 4 folhas, respectivamente. A duração de vida das folhas não foi afetada pelos períodos de descanso, entretanto, os valores médios foram muito superiores aos obtidos em estudos anteriores, portanto, não é um parâmetro eficaz para determinação do período de descanso. As taxas acumuladas das variáveis morfogênicas em estudo para o período de descanso de 1,5 a 2 folhas, somadas ao longo do ciclo de crescimento da cultura, determinam maior investimento da planta em lâminas verdes, o que resulta em melhores respostas morfogênicas do aspecto forrageiro.

Nitrogen deficiency inhibits leaf blade growth in Lolium perenne by increasing cell cycle duration and decreasing mitotic and post‐mitotic growth rates

Nitrogen deficiency severely inhibits leaf growth. This response was analysed at the cellular level by growing Lolium perenne L. under 7.5 mM (high) or 1 mM (low) nitrate supply, and performing a kinematic analysis to assess the effect of nitrogen status on cell proliferation and cell growth in the leaf blade epidermis. Low nitrogen supply reduced leaf elongation rate (LER) by 43% through a similar decrease in the cell production rate and final cell length. The former was entirely because of a decreased average cell division rate (0.023 versus 0.032 h(-1)) and thus longer cell cycle duration (30 versus 22 h). Nitrogen status did not affect the number of division cycles of the initial cell's progeny (5.7), and accordingly the meristematic cell number (53). Meristematic cell length was unaffected by nitrogen deficiency, implying that the division and mitotic growth rates were equally impaired. The shorter mature cell length arose from a considerably reduced post-mitotic growth rate (0.033 versus 0.049 h(-1)). But, nitrogen stress did not affect the position where elongation stopped, and increased cell elongation duration. In conclusion, nitrogen deficiency limited leaf growth by increasing the cell cycle duration and decreasing mitotic and post-mitotic elongation rates, delaying cell maturation.

Desempenho de vacas da raça Holandesa em pastagem de coastcross

Avaliou-se o desempenho produtivo de vacas da raça Holandesa mantidas em pastagem de coastcross (Cynodon dactylon (L.) Pears) fertilizada, irrigada e suplementada com 3 ou 6 kg de concentrado/vaca/dia. Dados de 108 lactações coletados durante três anos consecutivos (outubro/2000 a outubro/2003) foram analisados em um delineamento de blocos ao acaso com duas repetições por tratamento, utilizando-se nove animais por área e 18 por tratamento, com lotação fixa de cinco vacas/ha. Adotou-se o sistema de pastejo em lotação rotacionada, com um dia de ocupação e 25 e 35 dias de descanso dos piquetes, nas estações chuvosa e seca, respectivamente. A pastagem foi irrigada nos meses de menor precipitação e fertilizada com adubo formulado (NPK), distribuído a lanço em seis aplicações anuais. A disponibilidade de matéria seca foi de 7.280 e 6.167 kg/ha no início do pastejo, com resíduo pós-pastejo de 4.885 e 3.994 kg/ha, nas estações chuvosa (primavera/verão) e seca (outono/inverno), respectivamente. Durante parte do período experimental, algumas características morfogênicas da pastagem foram avaliadas, registrando-se disponibilidade de 83,9; 125,6 e 89,5 kg de MS de lâminas foliares/ha, nas estações de primavera, verão e outono, respectivamente. As produções médias diárias de leite (corrigidas para 3,5% de gordura) foram de 15,5 e 19,1 kg/vaca e de 77,8 e 94,0 kg/ha, quando foram fornecidos, para cada vaca, 3 e 6 kg de concentrado, respectivamente. Pastagem de coastcross, quando fertilizada e manejada adequadamente, viabiliza elevadas produtividades de leite por animal e por área, podendo ser recomendada para produção de leite em pastagens.

PHANTASTICA regulates development of the adaxial mesophyll in Nicotiana leaves.

Initiation and growth of leaf blades is oriented by an adaxial/abaxial axis aligned with the original axis of polarity in the leaf primordium. To investigate mechanisms regulating this process, we cloned the Nicotiana tabacum ortholog of PHANTASTICA (NTPHAN) and generated a series of antisense transgenics in N. sylvestris. We show that NSPHAN is expressed throughout emerging blade primordia in the wild type and becomes localized to the middle mesophyll in the expanding lamina. Antisense NSPHAN leaves show ectopic expression of NTH20, a class I KNOX gene. Juvenile transgenic leaves have normal adaxial/abaxial polarity and generate leaf blades in the normal position, but the adaxial mesophyll shows disorganized patterns of cell division, delayed maturation of palisade, and ectopic reinitiation of blade primordia along the midrib. Reversal of the phenotype with exogenous gibberellic acid suggests that NSPHAN, acting via KNOX repression, maintains determinacy in the expanding lamina and sustains the patterns of cell proliferation critical to palisade development.

Interaction of the UNIFOLIATA- TENDRILLED ACACIA gene with AFILA and TENDRIL- LESS genes in the determination of leaf blade growth and morphology in pea Pisum sativum

The pea Pisum sativum genes AFILA ( AF), TENDRIL- LESS ( TL) and UNIFOLIATA ( UNI) have been shown previously to be involved in the compound leaf blade patterning and AF and TL genes in leaf blade growth. Here, the interactions of the previously described UNI gene with AF and TL were studied using a new uni- tac allele and af and tl alleles, in the new background of cultivar Pusa Harbhajan. The leaf blades formed on the embryonic and mature pre- and post-flowering leaves from plants of AF TL UNI, af TL UNI, AF tl UNI, AF TL uni- tac, af tl UNI, af TL uni- tac, AF tl uni- tac and af tl uni- tac genotypes were measured for pinna growth in terms of their laminated and non-laminated organs. The investigation showed that UNI activates, and AF and TL repress the leaf blade ramification. UNI and AF act together in lamina-dominated pinna growth; we call this the AF-dependent leaflet development pathway. Presence of second AF-independent pathway for leaflet formation is described. TL and UNI are identified as antagonists of such pathway(s). UNI, AF and TL functions can up-regulate as well as down-regulate leaf-blade morphogenetic developmental events, in organ-specific manner.

The homeobox gene NTH23 of tobacco is expressed in the basal region of leaf primordia

We reported isolation and characterization of a homeobox gene from tobacco, NTH23. The homeodomain structure of NTH23 was highly homologous to the same regions of class 2 genes of the KN1-type homeobox (sharing more than 85% amino acid identity), but was less similar to class 1 genes of KN1-type. RNA gel blot analysis revealed that NTH23 was expressed in all organs we tested although the gene is primarily expressed in young leaves. To determine more precisely the spatial expression pattern of NTH23 in tobacco, a chimeric NTH23::GUS fusion gene was introduced into tobacco. The signal of GUS activity was observed at the basal part of leaf blade primordia in the NTH23::GUS transgenic tobacco plants. This observation suggests the possibility that NTH23 may be important for the lateral growth of leaf blades.

Growth Respiration in Rice Organs as Affected by Nitrogen Content.

The relationship between growth respiration and nitrogen content in rice organs was investigated. Top and root CO2 exchange rates were continuously measured for 5-6 days under different nutrient concentrations by lowering the light intensity with each passing day. There were significant positive correlations between the growth respiration rate in the top (Rgt) and dry matter increase in the top, and between the growth respiration rate in the root (Rgt) and dry matter increase in the root. Though, there were significant positive correlations between Rgt and leaf area expansion, and leaf dry matter increase, no significant relationship was found between Rgt and dry matter in leaf sheath. The growth respiration rate in each plant part was closely related to the dry matter increase and nitrogen increase. The nitrogen content of the leaf blade was higher than that of the leaf sheath. This suggests that growth respiration in the top is utilized more for the growth of leaf blade than that of leaf sheath. Moreover, the ranges of growth coefficient in the whole plant, top and root were from 0.56 to 1.26, 0.44 to 1.11, and 0.60 to 1.11 g g-1, respectively, under different nutrient conditions. The growth coefficient of each part increased as the result of nitrogen content in new biomass. The growth coefficient in the root was higher than that in the top when compared at the same value of the ratio of the increase in nitrogen. The slope of linear regression in the root was higher than that in the top. In this paper, it was determined quantitatively the relationship between nitrogen increase and growth coefficient in rice organs.

Abnormal cell divisions in leaf primordia caused by the expression of the rice homeobox gene OSH1 lead to altered morphology of leaves in transgenic tobacco.

Transgenic tobacco plants were generated carrying a rice homeobox gene, OSH1, controlled by the promoter of a gene encoding a tobacco pathogenesis-related protein (PR1a). These lines were morphologically abnormal, with wrinkled and/or lobed leaves. Histological analysis of shoot apex primordia indicates arrest of lateral leaf blade expansion, often resulting in asymmetric and anisotrophic growth of leaf blades. Other notable abnormalities included abnormal or arrested development of leaf lateral veins. Interestingly, OHS1 expression was undetectable in mature leaves with the aberrant morphological features. Thus, OSH1 expression in mature leaves is not necessary for abnormal leaf development. Northern blot and in situ hybridization analyses indicate that PR1a-OSH1 is expressed only in the shoot apical meristem and in very young leaf primordia. Therefore, the aberrant morphological features are an indirect consequence of ectopic OSH1 gene expression. The only abnormality observed in tissues expressing the transgene was periclinal (rather than anticlinal) division in mesophyll cells during leaf blade initiation. This generates thicker leaf blades and disrupts the mesophyll cell layers, from which vascular tissues differentiate. The OSH1 product appears to affect the mechanism controlling the orientation of the plane of cell division, resulting in abnormal periclinal division of mesophyll cell, which in turn results in the gross morphological abnormalities observed in the transgenic lines.