scholarly journals Sugar is an endogenous cue for juvenile-to-adult phase transition in plants

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Sha Yu ◽  
Li Cao ◽  
Chuan-Miao Zhou ◽  
Tian-Qi Zhang ◽  
Heng Lian ◽  
...  
Keyword(s):  
Phase Transition ◽  
Seed Germination ◽  
Gradual Increase ◽  
Leaf Primordia ◽  
Day Length ◽  
Developmental Timing ◽  
Transcriptional Level ◽  
Gradual Decline ◽  
Adult Phase ◽  
Photosynthetic Mutant

The transition from the juvenile to adult phase in plants is controlled by diverse exogenous and endogenous cues such as age, day length, light, nutrients, and temperature. Previous studies have shown that the gradual decline in microRNA156 (miR156) with age promotes the expression of adult traits. However, how age temporally regulates the abundance of miR156 is poorly understood. We show here that the expression of miR156 responds to sugar. Sugar represses miR156 expression at both the transcriptional level and post-transcriptional level through the degradation of miR156 primary transcripts. Defoliation and photosynthetic mutant assays further demonstrate that sugar from the pre-existing leaves acts as a mobile signal to repress miR156, and subsequently triggers the juvenile-to-adult phase transition in young leaf primordia. We propose that the gradual increase in sugar after seed germination serves as an endogenous cue for developmental timing in plants.

Glossy15 Controls the Epidermal Juvenile-to-Adult Phase Transition in Maize

1994 ◽  
Vol 6 (10) ◽  
pp. 1343 ◽  
Author(s):  
Stephen P. Moose ◽  
Paul H. Sisco
Keyword(s):  
Phase Transition ◽  
Adult Phase

Gradual increase in NaCl concentration overcomes inhibition of seed germination due to salinity stress in Sorghum bicolor (L.)

2005 ◽  
Vol 53 (2) ◽  
pp. 229-239 ◽  
Author(s):  
F. A: Faheed ◽  
A. M. Hassanein ◽  
M. M. Azooz
Keyword(s):  
Salt Stress ◽  
Seed Germination ◽  
Sorghum Bicolor ◽  
Growth Medium ◽  
Gradual Increase ◽  
Soluble Carbohydrates ◽  
Peroxidase Isoenzyme ◽  
Nacl Concentration ◽  
High Concentrations ◽  
Sorghum Bicolor L

A gradual increase in NaCl concentration in the growth medium was used as a strategy to adapt sorghum plants (Sorghum bicolor L.) to relatively high concentrations of NaCl. over a period of 15 days, a low percentage (22.2%) of sorghum seeds germinated in 200 mM NaCl, but most of the seedlings obtained (85.8%) died. On the other hand, plants subjected to adaptation by a gradual increase in NaCl concentration in the growth medium became capable of growth in soil containing 300 mM NaCl. In general, salinization induced a highly significant decrease in fresh and dry masses, and in the pigment content of sorghum seedlings. The content of free amino acids and soluble carbohydrates increased with a rise in the salinization level, especially in the adapted sorghum plants. The adapted plants contained less Na+ but more K+ compared to the unadapted plants, especially when the plants were subjected to relatively high NaCl concentration. Plants adapted in soil showed a new peroxidase isoenzyme form (POX-4). The peroxidase band POX-1 was detected under salt stress in both adapted and unadapted plants. Under salt stress, indophenol oxidase and glutamate oxaloacetate transaminase expressed new isoenzyme forms, IPOX-3 and IPOX-5, and GOT-2 and GOT-3, respectively. The induction of salt tolerance by a gradual increase in NaCl concentration for three weeks was recommended to overcome the inhibition of seed germination in saline soil.

scholarly journals Transcriptome Analysis and Identification of Genes Associated with Starch Metabolism in Castanea henryi Seed (Fagaceae)

2020 ◽  
Vol 21 (4) ◽  
pp. 1431 ◽  
Author(s):  
Bin Liu ◽  
Ruqiang Lin ◽  
Yuting Jiang ◽  
Shuzhen Jiang ◽  
Yuanfang Xiong ◽  
...  
Keyword(s):  
Seed Germination ◽  
Candidate Genes ◽  
Starch Content ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Starch Accumulation ◽  
Transcriptional Level ◽  
Potential Candidate ◽  
Starch Metabolism ◽  
Carbohydrate Storage

Starch is the most important form of carbohydrate storage and is the major energy reserve in some seeds, especially Castanea henryi. Seed germination is the beginning of the plant’s life cycle, and starch metabolism is important for seed germination. As a complex metabolic pathway, the regulation of starch metabolism in C. henryi is still poorly understood. To explore the mechanism of starch metabolism during the germination of C. henryi, we conducted a comparative gene expression analysis at the transcriptional level using RNA-seq across four different germination stages, and analyzed the changes in the starch and soluble sugar contents. The results showed that the starch content increased in 0–10 days and decreased in 10–35 days, while the soluble sugar content continuously decreased in 0–30 days and increased in 30–35 days. We identified 49 candidate genes that may be associated with starch and sucrose metabolism. Three ADP-glucose pyrophosphorylase (AGPase) genes, two nucleotide pyrophosphatase/phosphodiesterases (NPPS) genes and three starch synthases (SS) genes may be related to starch accumulation. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the expression levels of these genes. Our study combined transcriptome data with physiological and biochemical data, revealing potential candidate genes that affect starch metabolism during seed germination, and provides important data about starch metabolism and seed germination in seed plants.

scholarly journals Epigenetic control of juvenile-to-adult phase transition by the Arabidopsis SAGA-like complex

2015 ◽  
Vol 83 (3) ◽  
pp. 537-545 ◽  
Author(s):  
Ji-Yun Kim ◽  
Jee Eun Oh ◽  
Yoo-Sun Noh ◽  
Bosl Noh
Keyword(s):  
Phase Transition ◽  
Epigenetic Control ◽  
Adult Phase

Cone initiation and development before dormancy in yellow cedar (Chamaecyparis nootkatensis)

1974 ◽  
Vol 52 (9) ◽  
pp. 2075-2084 ◽  
Author(s):  
John N. Owens ◽  
Marje Molder
Keyword(s):  
Mitotic Activity ◽  
Lateral Branch ◽  
Leaf Primordia ◽  
Day Length ◽  
Chamaecyparis Nootkatensis ◽  
Seed Cone ◽  
Cone Development ◽  
Cone Apex ◽  
Lateral Branches ◽  
Pollen Cone

Vegetative shoots initiate leaves and lateral branches continuously from mid-April until the end of September. No buds with bud scales are formed and the vegetative apex is enclosed by leaf primordia at various stages of development. Pollen cones are initiated on proximal vegetative shoots during a 3-week period from mid-June to early in July. Transition to a pollen-cone apex is marked by an increase in mitotic activity in the apex and by the formation of a lateral branch in the axil of one of the last-formed leaf primordia, causing the apex to appear to branch dichotomously. The lateral branch remains at the base of the pollen cone and may resume growth the next year after the pollen cone is shed. Pollen-cone development continues until the end of September. Meiosis occurs during the last 2 weeks of August, and pollen develops during September. Seed cones are initiated on newly formed, distal axillary vegetative shoots during a 3-week period from late June to mid-July. Transition to a seed-cone apex is marked by an increase in mitotic activity followed by bract-scale initiation. Usually three ovules are initiated in the axil of each bract scale. Seed-cone development is complete by early September and the seed cones become dormant. The pattern of reproduction in yellow cedar is compared to other conifers and the possible relationships are discussed between time of cone initiation, sexuality of cones, and day length.

Floras of the Devonian - Mississippian Transition

1986 ◽  
Vol 15 ◽  
pp. 81-96 ◽  
Author(s):  
Stephen E. Scheckler
Keyword(s):  
Plant Communities ◽  
Middle Devonian ◽  
Gradual Increase ◽  
Late Devonian ◽  
Gradual Decline

Taken as a whole, Devonian and Carboniferous floras represent vastly different evolutionary stages in the colonization of the Earth's surface by plants. When only Late Devonian and Mississippian floras are considered, however, all of the floral innovations that led to and characterize the increasingly sophisticated plant communities of the Carboniferous began in the Famennian. When examined carefully enough, the stratigraphical succession of floras at the Devonian/Mississippian boundary reveals a gradual decline of typical Late Devonian elements and an equally gradual increase of plant types that eventually characterize the Early Mississippian. Furthermore, significant floral changes occur throughout the Late Devonian as archaic genera, that originated in Middle Devonian or earlier, disappear and new types appear that will become important in the Mississippian. Within the Mississippian too, the earliest floras contain elements left over from the Devonian, but show the origins or expansions of groups that ultimately were of great importance in the Pennsylvanian.

scholarly journals Jasmonate regulates juvenile-to-adult phase transition in rice

Development ◽  
2016 ◽  
Vol 143 (18) ◽  
pp. 3407-3416 ◽  
Author(s):  
Ken-ichiro Hibara ◽  
Miyako Isono ◽  
Manaki Mimura ◽  
Naoki Sentoku ◽  
Mikiko Kojima ◽  
...  
Keyword(s):  
Phase Transition ◽  
Adult Phase

scholarly journals Inhibition of Let-7 Maturation By Lin28b Controls Timing of Embryonic and Adult Myeloid Progenitor Phenotypes during Development

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 763-763
Author(s):  
Robert G Rowe ◽  
Leo D. Wang ◽  
Silvia Coma ◽  
Samantha Ross ◽  
Phi Nguyen ◽  
...  
Keyword(s):  
Rna Binding ◽  
Ectopic Expression ◽  
Developmental Timing ◽  
Transcriptional Level ◽  
Genetic Switch ◽  
Erythroid Progenitor ◽  
Myeloid Progenitor ◽  
The Impact ◽  
Fold Activation ◽  
Myeloid Progenitors

Abstract Within the mammalian fetal liver (FL) or adult bone marrow (ABM), terminally differentiated neutrophils, monocytes, and red blood cells emerge from a pool of multipotent common myeloid progenitors (CMPs). At steady state, the output of these cells is finally balanced but highly adaptable to the pathophysiologic requirements of the host. In the FL, erythroid output predominates to generate adequate oxygen transport for the metabolic demands of rapid organism growth in a hypoxic intrauterine environment; while granulocytic production comprises a larger balance of myelopoietic output in the ABM to provide innate immunity. The genetic regulators that specify timing of developmental stage-specific granulocytic/erythrocytic output from the myeloid progenitor pool have not been described. Initially defined as regulators of developmental timing in C. elegans, the mammalian Lin28a and Lin28b genes encode RNA binding-proteins capable of contributing to pluripotency induction in fully differentiated cells. Lin28 proteins exert their effects in part through inhibition of the maturation of the let-7 family of microRNAs - of which there are eight forms in mammals - that collectively drive cell terminal differentiation. Therefore, Lin28a/b expression is largely confined to embryonic tissues and is associated with the undifferentiated pluripotent or multipotent state in vivo. Given this role in regulation of multipotent cell function, we assessed the relative roles of theLin28/let-7 axis in developmental timing of myeloid progenitor phenotypes. We first analyzed patterns of let-7 expression during FL and ABM myelopoiesis. We found that several mature let-7 forms accumulated in CMPs during the transition from FL to ABM hematopoiesis (up to 30-fold induction as observed in let-7b in ABM compared to FL), coincident with 5-fold downregulation of the let-7 target and fetal-specific hematopoietic regulator Hmga2, indicating that the presence of mature let-7species may specify ABM-like myelopoiesis. To investigate this concept, we utilized a model of ectopic expression of LIN28B to block maturation of all let-7 species in ABM. Mice with activated LIN28B expression had a FL-like erythroid-dominant hematopoietic phenotype compared to controls (megakaryocyte-erythroid progenitor [MEP]:granulocyte-macrophage progenitor [GMP] ratio 3.9 ± 0.9 vs 0.8 ± 0.1, P = 0.005), along with blunted output of mature neutrophils in the ABM (P = 0.0001). Expression of LIN28B decreased formation of mature let-7 species in CMPs. Taken together, these results suggest that LIN28B expression reprograms ABM CMPs to a FL-like phenotype. To further define the Lin28-let-7 interaction in myelopoiesis, we analyzed the expression patterns of Lin28a and Lin28b as well as precursor let-7 microRNAs and their host genes during myeloid development. We observed up to 30-fold activation of precursor let-7 microRNAs and 4-fold activation of the polycistron encoding let-7b and let-7c2 coincident with 5-fold downregulation of Lin28b in CMPs during the transition from FL to ABM myelopoiesis. These results are consistent with mechanisms regulating levels of mature let-7 microRNAs at both the transcriptional and post-transcriptional level. We next characterized the effects of dysregulation of the Lin28b-let-7 interaction in the FL. Enforced expression of let-7g in mouse embryos drove increased granulocytic output in FL myeloid progenitors in culture (P = 0.001). While ectopic expression of Lin28 has been shown to confer fetal hematopoietic programs in other systems, the impact of loss of Lin28 genes on fetal hematopoiesis has not been reported. Fetal loss of Lin28b skewed the myeloid progenitor pool toward an ABM-like phenotype compared to wild-type animals (MEP:GMP 2.8 ± 0.5 vs. 4± 0.4, P = 0.1), though this phenotype is blunted due to the relative absence of let-7 precursors in the FL compared to the ABM, resulting in deregulated maturation of only a subset of mature let-7 forms. However, Lin28b-null FLs contained increased numbers of mature neutrophils (P = 0.005). Together, these data identify a Lin28/let-7 genetic switch with multiple levels of regulation that controls timing of the developmental myelopoietic phenotype. Disclosures No relevant conflicts of interest to declare.

scholarly journals Польова схожість насіння та збереженість рослин квасолі залежно від норми висіву насіння

2018 ◽  
pp. 30-36 ◽  
Author(s):  
А. О. Рожков ◽  
О. К. Труш
Keyword(s):  
Seed Germination ◽  
Considerable Increase ◽  
Gradual Increase ◽  
Plant Conservation ◽  
Weather Conditions ◽  
Vegetation Period ◽  
Short Supply ◽  
Field Germination ◽  
Maximum Quantity ◽  
Seed Sowing

Висвітлено результати трирічних досліджень щодо впливу норм висіву на польову схожість насіння, збереженість та кількість рослин перед збиранням квасолі звичайної різних за морфо-біотипом сортів. У дослідах визначено закономірності впливу норм висіву насіння на зміну цих показників у роки з різними погодними умовами веґетаційного періоду. Встановлено, що польова схожість насіння досліджуваних сортів квасолі за різних норм висіву була фактично на одному рівні. Більшою мірою на мінливість показників польової схожості насіння квасолі впливали погодні умови під час його проростання. Збереженість рослин до кінця веґетації більшою мірою залежала від норми висіву. За поступового її підвищення відмічалася закономірність більшого зниження показників збереженості рослин. Максимальне зниження показників збереженості рослин квасолі всіх сортів відмічалося в разі підвищення норми висіву від 600 до 700 тис. шт./га – на 6,2–6,8 %. У менш сприятливих погодних умовах 2015 і 2016 рр. максимальна кількість рослин перед збиранням була на варіантах норми висіву насіння 600 тис. шт./га. У ці роки підвищення норми висіву до 700 тис. шт./га не забезпечувало істотного збільшення кількості рослин квасолі перед збиранням. У сприятливіших погодних умовах 2017 р. найбільша кількість рослин всіх сортів була на варіантах максимальної норми висіву насіння – 700 тис. шт./га. Водночас ця прибавка, порівняно з нормою висіву 600 тис. шт./га, не перевищувала 5,0 %. The results of three year research concerning the influence of seed sowing rates on field seed germination, conservation and quantity of plants before harvesting common beans varities which are different according to the morphobiotype were elucidated. The influence power of seed sowing rates on the changeableness of these indices during the years of different weather conditions in vegetation period was determined. It was ascertained that field seed germination of haricot beans varieties under studying according to different seed sowing rates was on the same level. Weather conditions influenced the changeableness of the indices in field germination of haricot beans seeds most of all at the beginning of seed germination. The plants’ conservation depended on sowing rate mainly till the vegetation end. The gradual increase of seed sowing rate caused the considerable decrease of plant conservation indices. In particular, the increase of sowing rate from 300 to 400 thousand pcs/ha caused the decrease of plants conservation by average 1.2 %, and the increase of seed sowing rate from 600 to 700 thousand pcs/ha – by 6.5 %. This appropriateness was marked in all the varieties during all the years of the research. Panna variety was the best one among the varieties under studying concerning the plants conservation indices. Under more favourable weather conditions of growing the field germination of this variety was not higher than that of Pervomaiska and Dokuchaievska ones. But under conditions of moisture short supply, high temperature during germination this variety had an advantage. So, before harvesting the conservation of Panna varieties plants on all the variants of seed sowing rate was not lower than 67.0 %, while this index was lower than 60.0 % for Pervomaiska and Dokuchaievska varieties. Owing to higher indices of plants conservation for Panna variety during years of unfavorable weather conditions for seed germination, the plants quantity of this variety was higher than that of other ones when harvested. The maximum quantity indices of plants, before harvesting was noticed in 2015. In particular, before harvesting the plants quantity of Pervomais’ka, Dokuchaievs’ka and Panna varieties amounted average to 22.0, 23.0, 28.5 pcs/m2 correspondingly to seed sowing rates, according to the HIP05 the effect of this factor – 1.1 pcs/m2. The increase of seed sowing rate caused the gradual increase of plants quantity before harvesting. But the considerable increase of plants quantity before harvesting when seed sowing rate rose from 600 to 700 thousand pcs/ha took place only in 2017 when this increase was within HIP05 in 2015 and 2016. So, the increase of seed sowing rate in haricot beans varieties under studying from 600 to 700 pcs/ha can ensure the increase of plants quantity before harvesting only during the years of favourable weather conditions. According to the plants conservation indices, the plants quantity before harvesting under the influence of weather conditions was more stable concerning Panna variety. In particular, according to the seed sowing rates the maximum divergence scope of plants quantity in Dokuchaievs’ka, Pervomais’ka and Panna varieties amounted average 19.2, 14.1, and 11.4 % correspondingly during the years of research. Under the weather conditions in 2015 and 2016 before harvesting the maximum plants  quantity was on the variants of seed sowing rate amounting 600 thousand pcs/ha. The increase of sowing rate to 700 thousand pcs/ha did not ensure a considerable increase of haricot beans plants quantity before harvesting during these years. In 2017 the maximum quantity of haricot beans plants of all the varieties was on the variants of maximum seed sowing rate – 700 thousand pcs/ha. At the same time this increase did not exceed 5 % in comparison with the sowing rate amounting 600 thousand pcs/ha.

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