Metabolic signalling and the partitioning of resources in plant storage organs

1999 ◽  
Vol 133 (3) ◽  
pp. 243-249 ◽  
Author(s):  
NIGEL G. HALFORD

The most important harvested organs of crop plants, such as seeds, tubers and fruits, are often described as assimilate sinks. They play little or no part in the fixation of carbon through the production of sugars through photosynthesis, or in the uptake of nitrogen and sulphur, but import these assimilated resources to support metabolism and to store them in the form of starch, oils and proteins. Wild plants store resources in seeds and tubers to later support an emergent young plant. Cultivated crops are effectively storing resources to provide us with food and many have been bred to accumulate much more than would be required otherwise. For example, approximately 80% of a cultivated potato plant's dry weight is contained in its tubers, ten times the proportion in the tubers of its wild relatives (Inoue & Tanaka 1978). Cultivation and breeding has brought about a shift in the partitioning of carbon and nitrogen assimilate between the organs of the plant.

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 335
Author(s):  
Daniel Lizzi ◽  
Alessandro Mattiello ◽  
Alessio Adamiano ◽  
Guido Fellet ◽  
Emanuele Gava ◽  
...  

Most current studies on the relationships between plans and engineered nanomaterials (ENMs) are focused on food crops, while the effects on spontaneous plants have been neglected so far. However, from an ecological perspective, the ENMs impacts on the wild plants could have dire consequences on food webs and ecosystem services. Therefore, they should not be considered less critical. A pot trial was carried out in greenhouse conditions to evaluate the growth of Holcus lanatus L. (monocot) and Diplotaxis tenuifolia L. DC. (dicot) exposed to cerium oxide nanoparticles (nCeO2). Plants were grown for their entire cycle in a substrate amended with 200 mg kg−1nCeO2 having the size of 25 nm and 50 nm, respectively. nCeO2 were taken up by plant roots and then translocated towards leaf tissues of both species. However, the mean size of nCeO2 found in the roots of the species was different. In D. tenuifolia, there was evidence of more significant particle aggregation compared to H. lanatus. Further, biomass variables (dry weight of plant fractions and leaf area) showed that plant species responded differently to the treatments. In the experimental conditions, there were recorded stimulating effects on plant growth. However, nutritional imbalances for macro and micronutrients were observed, as well.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amanullah ◽  
Shah Khalid ◽  
Farhan Khalil ◽  
Mohamed Soliman Elshikh ◽  
Mona S. Alwahibi ◽  
...  

AbstractThe dry matter partitioning is the product of the flow of assimilates from the source organs (leaves and stems) along the transport route to the storage organs (grains). A 2-year field experiment was conducted at the agronomy research farm of the University of Agriculture Peshawar, Pakistan during 2015–2016 (Y1) to 2016–2017 (Y2) having semiarid climate. Four summer crops, pearl millet (Pennisetum typhoidum L.), sorghum (Sorghum bicolor L.) and mungbean (Vigna radiata L.) and pigeonpea (Cajanus cajan L.) and four winter crops, wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), fababean (Vicia faba) and rapeseed (Brassica napus) were grown under two irrigation regimes (full vs. limited irrigation) with the pattern of growing each crop either alone as sole crop or in combination of two crops in each intercropping system under both winter and summer seasons. The result showed that under full irrigated condition (no water stress), all crops had higher crop growth rate (CGR), leaf dry weight (LDW), stem dry weight (SDW), and spike/head dry weight (S/H/PDW) at both anthesis and physiological maturity (PM) than limited irrigated condition (water stress). In winter crops, both wheat and barley grown as sole crop or intercropped with fababean produced maximum CGR, LDW, SDW, S/H/PDW than other intercrops. Among summer crops, sorghum intercropped either with pigeon pea or with mungbean produced maximum CGR, LDW, SDW, and S/H/PDW at both growth stages. Sole mungbean and pigeon pea or pigeon pea and mungbean intercropping had higher CGR, LDW, SDW, S/H/PDW than millet and sorghum intercropping. On the other hand, wheat and barley grown as sole crops or intercropped with fababean produced maximum CGR, LDW, SDW, and S/H/PDW than other intercrops. Fababean grown as sole crop or intercropped with wheat produced higher CGR, LDW, SDW, and S/H/PDW at PM than intercropped with barley or rapeseed. From the results it was concluded that cereal plus legume intercropping particularly wheat/fababean in winter and sorghum/pigeon pea or sorgum/mungbean in summer are the most productive intercropping systems under both low and high moisture regimes.


2019 ◽  
Vol 6 (1) ◽  
pp. 411-433 ◽  
Author(s):  
Fernando García-Arenal ◽  
Francisco Murilo Zerbini

Viruses constitute the largest group of emerging pathogens, and geminiviruses (plant viruses with circular, single-stranded DNA genomes) are the major group of emerging plant viruses. With their high potential for genetic variation due to mutation and recombination, their efficient spread by vectors, and their wide host range as a group, including both wild and cultivated hosts, geminiviruses are attractive models for the study of the evolutionary and ecological factors driving virus emergence. Studies on the epidemiological features of geminivirus diseases have traditionally focused primarily on crop plants. Nevertheless, knowledge of geminivirus infection in wild plants, and especially at the interface between wild and cultivated plants, is necessary to provide a complete view of their ecology, evolution, and emergence. In this review, we address the most relevant aspects of geminivirus variability and evolution in wild and crop plants and geminiviruses’ potential to emerge in crops.


2007 ◽  
Vol 44 (03) ◽  
pp. 770-787
Author(s):  
N. Lanchier ◽  
C. Neuhauser

With the rapid adoption of transgenic crops, gene flow from transgenic crops to wild relatives through pollen dispersal is of significant concern and warrants both empirical and theoretical studies to assess the risk of introduction of transgenes into wild populations. We propose to use the (biased) voter model in a heterogeneous environment to investigate the effects of recurrent gene flow from transgenic crop to wild relatives. The model is defined on the d-dimensional integer lattice that is divided into two parts, Δ and Z d \ Δ. Individuals carrying the transgene and individuals carrying the wild type gene compete according to the evolution rules of a (biased) voter model on Z d \ Δ, while the process is conditioned to have only individuals carrying the transgene on Δ. Our main findings suggest that unless transgenes confer increased fitness in wild relatives, introgression of transgenes into populations of wild plants is slow and may even be reversible without intervention. Our study also addresses the effects of different spatial planting patterns of transgenic crops on the rate of introgression.


2007 ◽  
Vol 55 (2) ◽  
pp. 187-202 ◽  
Author(s):  
Anjula Pandey ◽  
Ajay Kumar Tomer ◽  
D. C. Bhandari ◽  
S. K. Pareek
Keyword(s):  

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