Exogenous spermidine regulates starch synthesis and the antioxidant system to promote wheat grain filling under drought stress

Wheat starch is one of the most important components in wheat grain and is extensively used as the main source in bread, noodles, and cookies. The wheat endosperm is composed of about 70% starch, so differences in the quality and quantity of starch affect the flour processing characteristics. Investigations on starch composition, structure, morphology, molecular markers, and transformations are providing new and efficient techniques that can improve the quality of bread wheat. Additionally, wheat starch composition and quality are varied due to genetics and environmental factors. Starch is more sensitive to heat and drought stress compared to storage proteins. These stresses also have a great influence on the grain filling period and anthesis, and, consequently, a negative effect on starch synthesis. Sucrose metabolizing and starch synthesis enzymes are suppressed under heat and drought stress during the grain filling period. Therefore, it is important to illustrate starch and sucrose mechanisms during plant responses in the grain filling period. In recent years, most of these quality traits have been investigated through genetic modification studies. This is an attractive approach to improve functional properties in wheat starch. The new information collected from hybrid and transgenic plants is expected to help develop novel starch for understanding wheat starch biosynthesis and commercial use. Wheat transformation research using plant genetic engineering technology is the main purpose of continuously controlling and analyzing the properties of wheat starch. The aim of this paper is to review the structure, biosynthesis mechanism, quality, and response to heat and drought stress of wheat starch. Additionally, molecular markers and transformation studies are reviewed to elucidate starch quality in wheat.

Download Full-text

The Effects of Short-Term Exposure to Low Temperatures During the Booting Stage on Starch Synthesis and Yields in Wheat Grain

Frontiers in Plant Science ◽

10.3389/fpls.2021.684784 ◽

2021 ◽

Vol 12 ◽

Author(s):

Wenjing Zhang ◽

Yan Zhao ◽

Lingyu Li ◽

Xu Xu ◽

Li Yang ◽

...

Keyword(s):

Low Temperatures ◽

Dry Matter ◽

Starch Content ◽

Starch Synthesis ◽

Grain Filling ◽

Starch Synthase ◽

Wheat Grain ◽

Short Term ◽

Booting Stage ◽

Grain Starch

Low temperatures (LT) in spring can have a major impact on the yields of wheat in winter. Wheat varieties with different cold sensitivities (the cold-tolerant Yannong 19 variety and the cold-sensitive Yangmai 18 variety) were used to study the responses of the wheat grain starch synthesis and dry material accumulation to short-term LT during the booting stage. The effects of short-term LT on the activities of key wheat grain starch synthesis enzymes, starch content and grain dry-matter accumulation were determined by exposing the wheat to simulated LT of from −2 to 2°C. Short-term LT stress caused a decrease in the fullness of the wheat grains along with decreased activities of adenosine diphosphate glucose pyrophosphorylase (AGPase, EC2.7.7.27), soluble starch synthase (SSS, EC2.4.1.21), granule-bound starch synthase (GBSS, EC2.4.1.21), and starch branching enzyme (SBE, EC2.4.1.18) at different spike positions during the filling stage. The rate of grain starch accumulation and starch content decreased with decreasing temperatures. Also, the duration of grain filling increased, the mean and the maximum filling rates were reduced and the quality of the grain dry-matter decreased. The number of grains per spike and the thousand-grain weight of the mature grains also decreased. Our data showed that short-term LT stress at the booting stage caused a decrease in the activities of key starch synthesis enzymes at the grain-filling stage. These changes reduced the accumulation of starch, decreased the filling rate, and lowered the accumulation of grain dry matter to ultimately decrease grain yields.

Download Full-text

Leaf-derived ABA regulates rice seed development via a transporter-mediated and temperature-sensitive mechanism

Science Advances ◽

10.1126/sciadv.abc8873 ◽

2021 ◽

Vol 7 (3) ◽

pp. eabc8873

Author(s):

Peng Qin ◽

Guohua Zhang ◽

Binhua Hu ◽

Jie Wu ◽

Weilan Chen ◽

...

Keyword(s):

Seed Development ◽

Starch Synthesis ◽

Biological Significance ◽

Grain Filling ◽

Temperature Sensitive ◽

Rice Seed ◽

Dependent Manner ◽

Long Distance ◽

Long Distance Transport ◽

Mechanistic Basis

Long-distance transport of the phytohormone abscisic acid (ABA) has been studied for ~50 years, yet its mechanistic basis and biological significance remain very poorly understood. Here, we show that leaf-derived ABA controls rice seed development in a temperature-dependent manner and is regulated by defective grain-filling 1 (DG1), a multidrug and toxic compound extrusion transporter that effluxes ABA at nodes and rachilla. Specifically, ABA is biosynthesized in both WT and dg1 leaves, but only WT caryopses accumulate leaf-derived ABA. Our demonstration that leaf-derived ABA activates starch synthesis genes explains the incompletely filled and floury seed phenotypes in dg1. Both the DG1-mediated long-distance ABA transport efficiency and grain-filling phenotypes are temperature sensitive. Moreover, we extended these mechanistic insights to other cereals by observing similar grain-filling defects in a maize DG1 ortholog mutant. Our study demonstrates that rice uses a leaf-to-caryopsis ABA transport–based mechanism to ensure normal seed development in response to variable temperatures.

Download Full-text

Effect of 28-homobrassinolide on the drought stress-induced changes in photosynthesis and antioxidant system of Brassica juncea L.

Acta Physiologiae Plantarum ◽

10.1007/s11738-009-0302-7 ◽

2009 ◽

Vol 31 (5) ◽

pp. 889-897 ◽

Cited By ~ 62

Author(s):

Q. Fariduddin ◽

S. Khanam ◽

S. A. Hasan ◽

B. Ali ◽

S. Hayat ◽

...

Keyword(s):

Drought Stress ◽

Brassica Juncea ◽

Antioxidant System ◽

Induced Changes

Download Full-text

Relationship between activities of key enzymes involved in starch synthesis and accumulation in maize inbred lines during grain filling

Russian Journal of Plant Physiology ◽

10.1134/s1021443708020131 ◽

2008 ◽

Vol 55 (2) ◽

pp. 249-255 ◽

Cited By ~ 4

Author(s):

J. J. Zhang ◽

Y. F. Hu ◽

Y. B. Huang

Keyword(s):

Starch Synthesis ◽

Grain Filling ◽

Inbred Lines ◽

Key Enzymes ◽

Maize Inbred Lines

Download Full-text

Effect of heat and drought stress on the structure and composition of arabinoxylan and β-glucan in wheat grain

Carbohydrate Polymers ◽

10.1016/j.carbpol.2013.12.005 ◽

2014 ◽

Vol 102 ◽

pp. 557-565 ◽

Cited By ~ 34

Author(s):

Marianna Rakszegi ◽

Alison Lovegrove ◽

Krisztina Balla ◽

László Láng ◽

Zoltán Bedő ◽

...

Keyword(s):

Drought Stress ◽

Wheat Grain

Download Full-text

Evaluation of Effect of Brassinolide in Brassica juncea Leaves under Drought Stress in Field Conditions

Horticulturae ◽

10.3390/horticulturae7110514 ◽

2021 ◽

Vol 7 (11) ◽

pp. 514

Author(s):

Naveen Naveen ◽

Nisha Kumari ◽

Ram Avtar ◽

Minakshi Jattan ◽

Sushil Ahlawat ◽

...

Keyword(s):

Drought Stress ◽

Brassica Juncea ◽

Antioxidant System ◽

Defense Mechanisms ◽

Crop Improvement ◽

Stress Conditions ◽

Flower Initiation ◽

Enzymatic Antioxidants ◽

Stress Indicators ◽

Enhanced Production

Drought stress is considered to be a major factor responsible for reduced agricultural productivity, because it is often linked to other major abiotic stresses, such as salinity and heat stress. Understanding drought-tolerance mechanisms is important for crop improvement. Moreover, under drought conditions, it is possible that growth regulators are able to protect the plants. Brassinosteroids not only play a regulatory role in plant growth, but also organize defense mechanisms against various tresses. This study aimed to evaluate the effect of brassinolide on physio-biochemical amendment in two contrasting cultivars (drought-tolerant RH 725, and drought-sensitive RH 749) of Brassica juncea under drought stress. Two foliar sprayings with brassinolide (10 and 20 mg/L) were carried out in both cultivars (RH 725 and RH 749) at two stages—i.e., flower initiation, and 50% flowering—under stress conditions. The results clearly revealed that the activities of antioxidative enzymes and non-enzymatic antioxidants (carotenoids, ascorbic acid, and proline) increased significantly in RH 725 at 50% flowering, whereas 20 mg/L of brassinolide showed the most promising response. The different oxidative stress indicators (i.e., hydrogen peroxide, malondialdehyde, and electrolyte leakage) decreased to a significant extent at 20 mg/L of brassinolide spray in RH 725 at 50% flowering. This study indicates that brassinolide intensifies the physio-biochemical attributes by improving the antioxidant system and photosynthetic efficiency in RH 725 at 50% flowering. It is assumed that enhanced production of proline, improvement of the antioxidant system, and reduction in the amount of stress indicators impart strength to the plants to combat the stress conditions.

Download Full-text

Heritability and mode of gene action determination for grain filling rate and relative water content in hexaploid wheat

Genetika ◽

10.2298/gensr1201025g ◽

2012 ◽

Vol 44 (1) ◽

pp. 25-32 ◽

Cited By ~ 3

Author(s):

Ahmad Golparvar

Keyword(s):

Drought Stress ◽

Water Content ◽

Relative Water Content ◽

Stress Condition ◽

Gene Action ◽

Grain Filling ◽

Stress Conditions ◽

Filling Rate ◽

Grain Filling Rate ◽

Relative Water

Mode of gene action, heritability and determination of the effective breeding strategy for improvement of physiological and traits specifically in drought stress conditions is very important. Therefore, this study was conducted by using two drought susceptible and tolerant wheat cultivars. Cultivars Sakha8 (tolerant) and Pishtaz (susceptible) as parents along with F1, F2, BC1 and BC2 generations were sown in a randomized complete block design with three replications in drought stress conditions. Results of analysis of variance indicated significant difference between generations as well as degree of dominance revealed over-dominance for the both traits. Fitting simple additive-dominance model designated that this model was not able to account for changes of traits relative water content and mean of grain filling rate. It was revealed that m-d-h-i-j model for relative water content and m-d-h-i model for mean of grain filling rate are the best models. Estimation of heritability and mode of gene action indicated that selection for improvement of traits studied in stress condition and specifically in early generations have medium genetic gain. In conclusion, grain filling rate is better than relative water content as indirect selection criteria to improve plant grain yield in drought stress condition.

Download Full-text