Development Of Tillering Bud Research Articles

Transcriptome Analysis Reveals the Potential Molecular Mechanisms of Tiller Bud Development in Orchardgrass.

Tillering is a special type of branching and one of the important contributors to the yield of cereal crops. Strigolactone and sucrose play a vital role in controlling tiller formation, but their mechanism has not been elucidated completely in most crops. Orchardgrass (Dactylis glomerata L.) is an important perennial forage with prominent tillering ability among crops. To date, the mechanism of tillering in orchardgrass is still largely unknown. Therefore, we performed a transcriptome and miRNA analysis to reveal the potential RNA mechanism of tiller formation under strigolactone and sucrose treatment in orchardgrass. Our results found that D3, COL5, NCED1, HXK7, miRNA4393-z, and miRNA531-z could be key factors to control tiller bud development in orchardgrass. In addition, strigolactones might affect the ABA biosynthesis pathway to regulate the tiller bud development of orchardgrass, which may be related to the expression changes in miRNA4393-z, NCED1, and D10. miRNA531-z could be involved in the interaction of strigolactones and sucrose in regulating tillering. These results will be further used to clarify the potential mechanism of tillering for breeding new high-tillering and high-production orchardgrass varieties and beneficial to improving the production and reproduction of crops.

Effects of different phosphorus levels on tiller bud development in hydroponic Phyllostachys edulis seedlings.

An appropriate amount of phosphate fertilizer can improve the germination rate of bamboo buds and increase the bamboo shoot output. However, the underlying biological mechanisms of phosphate fertilizer in bamboo shoot development have not been systematically reported. Herein, the effects of low (LP, 1μM), normal (NP, 50μM) and high (HP, 1000μM) phosphorus (P) on the growth and development of moso bamboo (Phyllostachys edulis) tiller buds were first investigated. Phenotypically, the seedling biomass, average number of tiller buds and bud height growth rate under the LP and HP treatments were significantly lower than those under the NP treatment. Next, the microstructure difference of tiller buds in the late development stage (S4) at three P levels was analyzed. The number of internode cells and vascular bundles were significantly lower in the LP treatments than in the NP treatments. The relative expression levels of eight P transport genes, eight hormone-related genes and four bud development genes at the tiller bud developmental stage (S2-S4) and the tiller bud re-tillering stage were analyzed with real-time polymerase chain reaction. The results showed that the expression trends for most P transport genes, hormone-related genes and bud development genes from S2 to S4 were diversified at different P levels, and the expression levels were also different at different P levels. In the tiller bud re-tillering stage, the expression levels of seven P transport genes and six hormone-related genes showed a downward trend with increasing P level. REV expression level decreased under LP and HP conditions. TB1 expression level increased under HP condition. Therefore, we conclude that P deficiency inhibits tiller bud development and re-tillering, and that P depends on the expression of REV and TB1 genes and auxin, cytokinin and strigolactones synthesis and transporter genes to mediate tiller bud development and re-tillering.

MiR319‐targeted OsTCP21 and OsGAmyb regulate tillering and grain yield in rice

Multiple genes and microRNAs (miRNAs) improve grain yield by promoting tillering. MiR319s are known to regulate several aspects of plant development; however, whether miR319s are essential for tillering regulation remains unclear. Here, we report that miR319 is highly expressed in the basal part of rice plant at different development stages. The miR319 knockdown line Short Tandem Target Mimic 319 (STTM319) showed higher tiller bud length in seedlings under low nitrogen (N) condition and higher tiller bud number under high N condition compared with the miR319a-overexpression line. Through targets prediction, we identified OsTCP21 and OsGAmyb as downstream targets of miR319. Moreover, OsTCP21 and OsGAmyb overexpression lines and STTM319 had increased tiller bud length and biomass, whereas both were decreased in OsTCP21 and OsGAmyb knockout lines and OE319a. These data suggest that miR319 regulates rice tiller bud development and tillering through targeting OsTCP21 and OsGAmyb. Notably, the tiller number and grain yield increased in STTM319 and overexpression lines of OsTCP21 and OsGAmyb but decreased in OE319a and knockout lines of OsTCP21 and OsGAmyb. Taken together, our findings indicate that miR319s negatively affect tiller number and grain yield by targeting OsTCP21 and OsGAmyb, revealing a novel function for miR319 in rice.

OsWUS promotes tiller bud growth by establishing weak apical dominance in rice

Two branching strategies are exhibited in crops: enhanced apical dominance, as in maize; or weak apical dominance, as in rice. However, the underlying mechanism of weak apical dominance remains elusive. OsWUS, an ortholog of Arabidopsis WUSCHEL (WUS) in rice, is required for tiller development. In this study, we identified and functionally characterized a low-tillering mutant decreased culm number 1 (dc1) that resulted from loss-of-function of OsWUS. The dc1 tiller buds are viable but repressed by the main culm apex, leading to stronger apical dominance than that of the wild-type (WT). Auxin response is enhanced in the dc1 mutant, and knocking out the auxin action-associated gene ABERRANT SPIKELET AND PANICLE 1 (ASP1) de-repressed growth of the tiller buds in the dc1 mutant, suggesting that OsWUS and ASP1 are both involved in outgrowth of the rice tiller bud. Decapitation triggers higher contents of cytokinins in the shoot base of the dc1 mutant compared with those in the WT, and exogenous application of cytokinin is not sufficient for sustained growth of the dc1 tiller bud. Transcriptome analysis indicated that expression levels of transcription factors putatively bound by ORYZA SATIVA HOMEOBOX 1 (OSH1) are changed in response to decapitation and display a greater fold change in the dc1 mutant than that in the WT. Collectively, these findings reveal an important role of OsWUS in tiller bud growth by influencing apical dominance, and provide the basis for an improved understanding of tiller bud development in rice.

Genome-wide transcriptome profiling provides overwintering mechanism of Agropyron mongolicum

BackgroundThe mechanism of winter survival for perennials involves multiple levels of gene regulation, especially cold resistance. Agropyron mongolicum is one important perennial grass species, but there is little information regarding its overwintering mechanism. We performed a comprehensive transcriptomics study to evaluate global gene expression profiles regarding the winter survival of Agropyron mongolicum. A genome-wide gene expression analysis involving four different periods was identified. Twenty-eight coexpression modules with distinct patterns were performed for transcriptome profiling. Furthermore, differentially expressed genes (DEGs) and their functional characterization were defined using a genome database such as NT, NR, COG, and KEGG.ResultA total of 79.6% of the unigenes were characterized to be involved in 136 metabolic pathways. In addition, the expression level of ABA receptor genes, regulation of transcription factors, and a coexpression network analysis were conducted using transcriptome data. We found that ABA receptors regulated downstream gene expression by activating bZIP and NAC transcription factors to improve cold resistance and winter survival.ConclusionThis study provides comprehensive transcriptome data for the characterization of overwintering-related gene expression profiles in A. mongolicum. Genomics resources can help provide a better understanding of the overwintering mechanism for perennial gramineae species. By analyzing genome-wide expression patterns for the four key stages of tiller bud development, the functional characteristics of the DEGs were identified that participated in various metabolic pathways and have been shown to be strongly associated with cold tolerance. These results can be further exploited to determine the mechanism of overwintering in perennial gramineae species.

Morphological studies on tillering habits in temperate herbage grasses V. Patterns of tillering and tiller bud development of some grasses under contrasting light regimes

Morphological studies on tillering habits in temperate herbage grasses V. Patterns of tillering and tiller bud development of some grasses under contrasting light regimes

寒地型イネ科牧草の分げつ習性に関する形態学的研究 : I.好適環境条件下におけるオーチャードグラス幼植物の分げつの発生と分げつ芽の形成・発育-その規則性について

寒地型イネ科牧草の分げつ習性に関する形態学的研究 : I.好適環境条件下におけるオーチャードグラス幼植物の分げつの発生と分げつ芽の形成・発育-その規則性について

Subsurface Compaction Effects on Tillering and Nitrogen Accumulation in Wheat

AbstractCompaction in the 0.05‐ to 0.30‐m depth may limit tillering and N accumulation in wheat (Triticum aestivum L.); these effects may be yield reducing. Before imposing compaction treatments in a field study in Minnesota, perforated small‐diameter tubing was buried in a Waukegan silt loam (sandy skeletal, mixed, mesic Typic Hapludoll) at a depth of 0.2 m in all plots. Compacted plots each received four passes with a heavy vibrating roller, while control plots were disk plowed and then disk harrowed. All plots were then surface roto‐tilled and seeded to wheat. At early tillering a K15NO3 solution was applied to the subsurface via the tubing. Plants sampled for 15N/N recovery 24 h after 15N application, at anthesis, and at maturity showed no significantly different 15N or N concentration or accumulation per culm/ individual organ in response to compaction. Because subsurface compaction reduced tillering, N uptake in the grain and straw was reduced by 21 and 30%, respectively. After the 0.10‐m surface layer was removed from all plots in a field study on a clay loam soil (Typic Calcixerolls) in Morocco, the subsurface was compacted by four passes with a 7.5‐ton tractor. Soil was then replaced, leveled, and only the control plots were disk plowed and disk harrowed twice. Both compacted and control plots were roto‐tilled and seeded. Nitrogen concentration and accumulation per culm/individual organ immediately after tillering was reduced less than 5% by the compacted treatment in both 1982 and 1983. Reduced tillering in the compacted treatment reduced average N uptake 11 and 28% in the grain and straw, respectively. In all three tests N concentration in the shoot at the end of tillering was high; yet it was higher in the compacted treatment. Then N concentration and uptake was reduced by compaction on a per culm basis at maturity, and earlier in one of the field studies. Root length density was reduced in the compacted zone in response to greater penetrometer load and higher bulk density. Tiller bud development was suppressed by the compaction treatment as much as 20% even though concentrations of N were high in the shoot. Tiller losses and declines of N concentration in the shoot in the post tillering stages were nearly the same in both treatments. Additional N before tillering therefore cannot overcome the adverse influence of subsoil compaction.

Effects of plant growth regulators on tiller bud outgrowth in uniculm cereals

SummaryPlant growth regulators were applied either to seeds or to leaves of uniculm selections of barley and wheat. None of the treatments stimulated the growth and development of tiller buds in the barley selection. In contrast, in wheat the development of tiller buds was readily stimulated and tillers were produced following treatment with Terpal, Cerone, TIBA or nitrate. In Terpal and Cerone treated plants, the stimulation of tiller bud outgrowth and tillering was accompanied by a marked retardation of growth in the main shoot. The growth of the tillers was however not sustained in any of the treatments, and so at maturity all plants were virtually uniculm. The results are discussed in relation to the different overall response of the two species, the death of tillers, and the hormonal regulation of tiller bud development.

Effects of Clipping Disposal, Nitrogen, and Growth Retardants on Thatch and Tiller Density in Zoysiagrass

Accumulation of thatch is a cultural problem affecting managers of ‘Meyer’ zoysiagrass (Zoysia japonica Steud.). Research was undertaken to investigate the effects of clipping disposal, N fertilization, and growth retardants on thatch accumulation and resistance of plant tissue to decomposition. In a 2‐yr field study, clipping disposal (removed or left on plots); N fertilization (98.0 kg ha−1 yr−1); and the growth retardants mefluidide (N‐[2,4‐dimethyl‐5‐[[(trifluromethyl)‐sulfonyl]amino]phenyl]acetamide) applied twice each year at 0.4 and 0.8 kg a.i. ha 1, and flurprimidol (α‐(1‐methylethyl)‐α(4‐trifluromethoxy)phenyl)‐5‐pyrimidine‐methanol) applied at 1.7, and 2.2 kg a.i. ha−1 twice in each year were examined for their effects on thatch, tiller density, verdure, and stolon weight. Relative degradation of leaves and stolons was compared by in vitro digestion in a prepared cellulase solution. Returned clippings increased thatch by only 3.4% and decreased tiller density by 12% when N was applied. Nitrogen increased thatch and tiller density. Growth retardants did not affect thatch. Degradation of leaves (64%) by the cellulase solution exceeded that of stolons (60%). The reduction in tiller density associated with returned clippings may be due to shading from clippings in the turf canopy resulting in leaf etiolation and reduced tiller bud development. Leaf clippings contributed slightly to thatch accumulation, most likely due to their physical accumulation rather than indirect effects of N recycling. Both stolons and, to a lesser degree, leaves appear to contribute to thatch accumulation in Meyer zoysiagrass. Decreased use of N in the culture of Meyer zoysiagrass, within limits required for acceptable appearance, might help reduce thatch accumulation. Removal of clippings is not recommended for thatch control considering their small contribution to thatch cover and due to the benefit of recycled nutrients.

Leaf and tiller growth ofLolium perenneandAgrostisspp. and leaf appearance rates ofTrifolium repensin set-stocked and rotationally grazed hill pastures

Abstract Growth components of Lotium perenne and Agrostis spp. tillers and Trifolium repens stolon apices were compared for one year under set stocking and rotational grazing with sheep on hill pastures which had had low and high levels of fertiliser input. Leaf appearance rates of L. perenne and Agrostis spp. were unaffected by grazing management or fertiliser level. Leaf appearance in T. repens was also largely unaffected by treatments except in summer when rotational grazing allowed some relief from defoliation stresses and leaf appearance rates were greater than under set stocking during 3 grazing rotations. T. repens leaf appearance rates were slower in winter and increased later in spring than the grasses. For most of the year, tiller bud development in L. perenne was well below the maximum possible because of mutual shading in dense swards (mean total tiller density 29700 tillers/m2 under set stocking and 20 l00/m2 under rotational grazing). L. perenne lamina lengths, tiller lengths, and leaf extension rates were approximately twice those of Agrostis spp. Leaf extension rates were faster under rotational grazing for L. perenne and Agrostis spp. but tiller densities of both species were greater under set stocking. Total leaf growth per unit area is, therefore, likely to be similar under both managements. Slightly greater L. perenne growth and less Agrostis spp. growth per unit area under rotational grazing than under set stocking is indicated by a comparison of individual tiller growth and tiller density data. The results are discussed in relation to published findings from the same systems.

Manipulation of Apical Dominance in Sorghum with Growth Regulators 1

The hormonal control of apical dominance (inhibition of lateral bud formation and development) in sorghum [Sorghum bicolor (L.) Moench] was studied by applying plant growth regulators to two cultivars—SM100 (weak apical dominance) and BT×378 (strong apical dominance). In the field, SM100 produced an average of 1 tiller per 2 plants before anthesis and BT×378 produced none. Following anthesis, apical dominance diminished in both cultivars. Spray applications of 0.2 mM gibberellic acid (GA3) during the initial 7 weeks of seedling growth completely inhibited bud outgrowth before anthesis in SM100. Bud outgrowth increased rapidly in both cultivars after termination of GA3 applications. This rapid increase in bud outgrowth was similar to the normal release from apical dominance ocurrlng in untreated plants following anthesis except that it was earlier, occurred at a more rapid rate, and a larger final number of buds was released. Thus, two aspects of the normal pattern of tiller bud development were mimicked by GA3 application: i) intensification of the inhibition of bud outgrowth before anthesis and ii) acceleration of bud outgrowth occurring after anthesis. In plants grown hydroponically in the greenhouse, GA3 again inhibited bud outgrowth in SM100 plants during the vegetative period. A role for gibberellin(s) in sorghum apical dominance is suggested because bud outgrowth was promoted in BT×378 plants by a gibberellin synthesis inhibitor, ancymidol. Evidence for the participation of auxins and cytokinins in sorghum apical dominance was also obtained. The auxin naphthaleneacetic acid inhibited bud outgrowth in SM100. In BT×378 the auxin transport inhibitor naphthylphthalamic acid and the cytokinin benzyladenine caused bud outgrowth which resembled that obtained by apical bud removal.

EFFECTS OF SOME GROWTH REGULATORS ON TILLER BUD ELONGATION IN CEREALS

SUMMARYThe effects of foliar and root applied 6‐benzylamino‐9‐(tetrahydropyran‐2‐yl)‐9H‐purine (PBA), 6‐benzylamino‐purine (BAP), indole‐3‐acetic acid (IAA) or gibberellic acid (GA3) on tiller bud growth were examined in cereal seedlings. Generally IAA and GA3 inhibited tiller bud growth whilst the synthetic cytokinins both markedly promoted growth. Some observations on stem and root growth were also recorded. The results are discussed with respect to the diversion of both assimilates and cytokinins and appear to favour the view that tiller bud development is controlled by a competition for assimilates with the roots and main shoot.

Seasonal Variations of the Tiller Bud Development in Each Node of Orchardgrass Shoot

Seasonal Variations of the Tiller Bud Development in Each Node of Orchardgrass Shoot

Studies on the Tillering Primordium and Tillering, Bud in Rice Seedlings : (10) Effect of potassium deficiency on the development of tillering buds

This experiment was undertaken to determine the effect of nitrogen deficiency on the development of tillering bud in rice seedling by water culture method. Design of experiment and composition of nutrient solution are shown in table 1 and 2. Nutrient solution of nitrogen deficiency used for this study omitted the N-ion from the standard nutrient solution (shown in table 2). The results are summarized as follows; In the rice seedling which has been grown under nitrogen deficient condition since the seeding (of rice plant): 1. In case the plant was supplied with nitrogen since the early stage of the 3rd foliage leaf, the 2nd tillering bud grew well. 2. In case the plant was supplied with nitrogen since the early stage of the 4th foligage leaf, the development of the 2nd tillering bud was remarkably inhibited but the 3rd tillering bud grew well. 3. In case the plant was supplied with nitrogen since the early stage of the 5th foliage leaf, not only the development of the 2nd tillering bud but also that of the 3 rd one were remarkably inhibited, but the 4th tillering bud and the following 5th, 6th, 7th etc. showed remarkable growth. 4. In case the plant was grown under nitrorgen deficient condition throghout the whole growing periods of the plant, all the tillering buds in the plant were rested to grow. From these results, the rice seedling which was supplied with nitrogen after having been grown under nitrogen dificient condition in the early growth (of rice plant) it was concluded that the development of tillering buds by the differences of growing stages in the plant supplied nitrogen, were many differences as to the development of tillering bud in the plant, was differently affected in response to the period of nitrogen deficieney, especially the effects on the development of tillering buds in as such low stem-nodes as the 2nd and 3 rd etc. in main stem were remarkable.

Studies on the Tillering Primordium and Tillering Bud in Rice Seedlings : (8) Effect of nitrogen deficiency on the development of tillering bud

This experiment was undertaken to determine the effect of nitrogen deficiency on the development of tillering bud in rice seedling by water culture method. Design of experiment and composition of nutrient solution are shown in table 1 and 2. Nutrient solution of nitrogen deficiency used for this study omitted the N-ion from the standard nutrient solution (shown in table 2). The results are summarized as follows; In the rice seedling which has been grown under nitrogen deficient condition since the seeding (of rice plant): 1. In case the plant was supplied with nitrogen since the early stage of the 3rd foliage leaf, the 2nd tillering bud grew well. 2. In case the plant was supplied with nitrogen since the early stage of the 4th foligage leaf, the development of the 2nd tillering bud was remarkably inhibited but the 3rd tillering bud grew well. 3. In case the plant was supplied with nitrogen since the early stage of the 5th foliage leaf, not only the development of the 2nd tillering bud but also that of the 3 rd one were remarkably inhibited, but the 4th tillering bud and the following 5th, 6th, 7th etc. showed remarkable growth. 4. In case the plant was grown under nitrorgen deficient condition throghout the whole growing periods of the plant, all the tillering buds in the plant were rested to grow. From these results, the rice seedling which was supplied with nitrogen after having been grown under nitrogen dificient condition in the early growth (of rice plant) it was concluded that the development of tillering buds by the differences of growing stages in the plant supplied nitrogen, were many differences as to the development of tillering bud in the plant, was differently affected in response to the period of nitrogen deficieney, especially the effects on the development of tillering buds in as such low stem-nodes as the 2nd and 3 rd etc. in main stem were remarkable.

Studies on the Tillering Primordium and Tillering Bud in Rice Seedlings : (9) Effect of phosphorus deficiency on the development of tillering bud

Studies on the Tillering Primordium and Tillering Bud in Rice Seedlings : (9) Effect of phosphorus deficiency on the development of tillering bud

Studies on the tillering in the genus Allium. V

Some examples of abnormal leaves and abnormal tillerings observed in Welsh onion are reported. It may be summarized as follows: 1. Several rare cases where abnormal leaves having two laminae on a leaf sheath were observed in var. Iwatsuki, Kaga-Ippon, Asaki-Kujyo and Matsu-moto-Ippon. These were designated as “di-lamina leaf”. Almost all of these leaves were formed on the second or third node after the first tiller occurred. As shown in Fig. 5, di-lamina leaves may be di-vided into three fundamental types by the arrange-ment of laminae. 2. When the n-th leaf was dwarf and its develop-ment was very slow, the emerging date of n-th leaf was frequently later than that of (n+1)th leaf in the normal order of emergence. Examples of such cases were occasionally observed on the first leaf of tillers or new vegetative axil-lary buds. 3. Although the normal tillering bud of Welsh onion generally appears singly on a node, occasional-ly two or more tillering buds appeared on the same node. This abnormal phenomenon was designated as “poly-tillering”. The poly-tillerings were observed rarely on the nodes of normal leaves, but more frequently on the nodes of di-lamina leaves. Almost all of these poly-tillerings were formed on the first or second node after the first tiller occurred. 4. Sometimes, the development of tillering bud was so slow that the tiller appeared too late from the leaf sheath of preceding node for the normal tiller. These abnormal tillers may be divided into the following two types: a) Only the first leaf is dwarf, but the second and subsequent leaves show a normal develop-ment. b) All leaves of tiller are dwarf. 5. At times the abnormal tillers which developed the first leaf alone were observed. These examples were frequently observed in the last stage of the growing season.

Studies on the tillering primordium and tillering bud in rice seedlings : (6) The influence of seeding depth on the development of tillering primordium and tillering bud : II. In the case of Flooding condition

1. This experiment was made in the same way as described in the 5 th report except that it was carried out under flooding condition. 2. Seeding depth was 0.5 cm, 1 cm, 2 cm, and 3 cm. 3. The result of experiment is summarized as follows. The development of tillering primordium and bud observed under each seeding depth, was generally the same as observed under not flooded condition, that is, good developments & growth for shallow sowing, and as the sowing becomes deeper the growth was retarded. However, the difference of the development of the each tillering bud induced by the different seeding depth was much greater than that under the not flooded condition.