Sensing of soil water status and the regulation of plant growth and development

1990 ◽  
Vol 13 (7) ◽  
pp. 709-719 ◽  
Author(s):  
W. J. DAVIES ◽  
T. A. MANSFIELD ◽  
A. M. HETHERINGTON
HortScience ◽  
2010 ◽  
Vol 45 (8) ◽  
pp. 1196-1204 ◽  
Author(s):  
Juan Carlos Díaz-Pérez

Plastic mulches are widely used for the production of vegetables. There are numerous studies on the use of plastic mulches for peppers, although relatively few have focused on the microenvironmental and physiological impacts of plastic mulches on bell pepper. The objectives were to determine the effects of plastic film mulches on root zone temperature (RZT), soil water status, incidence of thrips and Tomato spotted wilt (TSW), plant growth, gas exchange, accumulation of mineral nutrients, and fruit yield in bell pepper. The study was conducted in Tifton, GA, in the Fall of 2002 and the Spring of 2003 using eight colored plastic mulches. Plastic mulch color influenced the microenvironmental, physiological, and yield responses of bell pepper plants. Plastic film mulches differed in their soil-warming ability with RZTs in both spring and fall being highest in black mulches and lowest in silver mulches. The percentage of photosynthetically active radiation (PAR) reflected from the mulches was highest in silver mulches and lowest in black mulches. The mean RZT under the plastic mulch decreased with increasing percentages of reflected PAR. The number of thrips per flower and the incidence of TSW in mature plants were not significantly different among plastic mulch treatments. The number of thrips per flower had no relationship with the percentage of reflected PAR or with RZT. Plastic mulch treatments had no significant effect on soil water status. Neither soil water content nor soil water potential had a relationship with RZT. In the fall season, during the first 28 days after transplanting, plant growth attributes were among the highest in silver mulches and the lowest in black mulches. Gas exchange and accumulation of mineral nutrients in the leaves and the fruit were not significantly affected by plastic mulches. Both marketable and total yields were higher on silver mulches and lowest on black mulch in the fall, whereas they were in general higher on silver with a black strip mulch and lowest on white and silver1 mulches in the spring. The reduced plant growth and fruit yields in black mulches during the fall were probably the result of the increased RZTs, and thus higher heat accumulation, that resulted in higher plant heat stress conditions compared with silver and white mulches. Fruit yield decreased with mean seasonal RZTs above 27.5 °C. The optimal range of RZT for bell pepper fruit yield was computed to be 25 to 27.5 °C or less.


2015 ◽  
Vol 58 ◽  
pp. 61-70 ◽  
Author(s):  
Paul B. Larsen

Ethylene is the simplest unsaturated hydrocarbon, yet it has profound effects on plant growth and development, including many agriculturally important phenomena. Analysis of the mechanisms underlying ethylene biosynthesis and signalling have resulted in the elucidation of multistep mechanisms which at first glance appear simple, but in fact represent several levels of control to tightly regulate the level of production and response. Ethylene biosynthesis represents a two-step process that is regulated at both the transcriptional and post-translational levels, thus enabling plants to control the amount of ethylene produced with regard to promotion of responses such as climacteric flower senescence and fruit ripening. Ethylene production subsequently results in activation of the ethylene response, as ethylene accumulation will trigger the ethylene signalling pathway to activate ethylene-dependent transcription for promotion of the response and for resetting the pathway. A more detailed knowledge of the mechanisms underlying biosynthesis and the ethylene response will ultimately enable new approaches to be developed for control of the initiation and progression of ethylene-dependent developmental processes, many of which are of horticultural significance.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 508e-508
Author(s):  
Bin Liu ◽  
Royal D. Heins

A concept of ratio of radiant to thermal energy (RRT) has been developed to deal with the interactive effect of light and temperature on plant growth and development. This study further confirms that RRT is a useful parameter for plant growth, development, and quality control. Based on greenhouse experiments conducted with 27 treatment combinations of temperature, light, and plant spacing, a model for poinsettia plant growth and development was constructed using the computer program STELLA II. Results from the model simulation with different levels of daily light integral, temperature, and plant spacing showed that the RRT significantly affects leaf unfolding rate when RRT is lower than 0.025 mol/degree-day per plant. Plant dry weight is highly correlated with RRT; it increases linearly as RRT increases.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1311
Author(s):  
Magdalena Chmur ◽  
Andrzej Bajguz

Brassinolide (BL) represents brassinosteroids (BRs)—a group of phytohormones that are essential for plant growth and development. Brassinazole (Brz) is as a synthetic inhibitor of BRs’ biosynthesis. In the present study, the responses of Wolffia arrhiza to the treatment with BL, Brz, and the combination of BL with Brz were analyzed. The analysis of BRs and Brz was performed using LC-MS/MS. The photosynthetic pigments (chlorophylls, carotenes, and xanthophylls) levels were determined using HPLC, but protein and monosaccharides level using spectrophotometric methods. The obtained results indicated that BL and Brz influence W. arrhiza cultures in a concentration-dependent manner. The most stimulatory effects on the growth, level of BRs (BL, 24-epibrassinolide, 28-homobrassinolide, 28-norbrassinolide, catasterone, castasterone, 24-epicastasterone, typhasterol, and 6-deoxytyphasterol), and the content of pigments, protein, and monosaccharides, were observed in plants treated with 0.1 µM BL. Whereas the application of 1 µM and 10 µM Brz caused a significant decrease in duckweed weight and level of targeted compounds. Application of BL caused the mitigation of the Brz inhibitory effect and enhanced the BR level in duckweed treated with Brz. The level of BRs was reported for the first time in duckweed treated with BL and/or Brz.


Author(s):  
Yuki Nakamura ◽  
Anh H. Ngo

The article Non-specific phospholipase C (NPC): an emerging class of phospholipase C in plant growth and development, was originally published Online First without Open Access.


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