Novel insights into the effect of drought stress on the development of root and caryopsis in barley

Abstract

Drought is a common natural disaster in barley production, which restricts the growth and development of barley roots and caryopses seriously, thereby decreasing yield and debasing grain quality. However, mechanisms for how drought stress affects barley caryopses and roots development under drought stress are unclear. In this paper, Suluomai1 was treated with drought from flowering to caryopses mature stage. The morphological and structural changes in roots growth and caryopses development of barley were investigated. Drought stress increased root/shoot ratio and eventually led to the 20.16% reduction of ear weight and 7.75% reduction of 1,000-grain weight by affecting the biomass accumulation of roots and caryopses. The barley roots under drought had more lateral roots while the vessel number and volume of roots decreased. Meanwhile, drought stress accelerated the maturation of caryopses, resulting in a decrease in the accumulation of starch but a significant increase of protein accumulation in barley endosperm. There was a significantly positive correlation (0.76) between the area of root vessel and the relative area of protein in endosperm cells under normal condition and drought increased the correlation coefficient (0.81). Transcriptome analysis indicated that drought induced differential expressions of genes in caryopses were mainly involved in encoding storage proteins and protein synthesis pathways. In general, drought caused changes in the morphology and structure of barley roots, and the roots conveyed stress signals to caryopses, inducing differential expression of genes related to protein biosynthesis, ultimately leading to the increase in the accumulation of endosperm protein. The results not only deepen the study on drought mechanism of barley, but also provide theoretical basis for molecular breeding, high-yield cultivation and quality improvement in barley.

The relationship between characteristics of root morphology and grain filling in wheat under drought stress

“…Wheat root and caryopsis samples were collected as previously described in Li et al (2020) . The root samples were the segments of secondary root which were 2 cm from the stem axis base and the caryopsis samples selected were in the same position of the middle of main spike.…”

“…Image-Pro Plus 6.0 and Photoshop CC 2017 were used to analyze the relative areas of amyloplast and protein body in endosperm based on microphotographs, according to the method previously described ( Yu et al, 2015a ; Li et al, 2020 ). Specifically, the central endosperm region was photographed at 200 times magnification.…”

MicroRNA172b-5p/trehalose-6-phosphate synthase module stimulates trehalose synthesis and microRNA172b-3p/AP2-like module accelerates flowering in barley upon drought stress

“…Continuous, mild drought in barley has been reported to delay heading and flowering and resulted in a decreased number of spikes and seeds ( Gol et al., 2021 ). However, severe drought along with the lower biomass accumulation accelerates the caryopsis maturation and increases the content of protein in mature caryopses ( Li et al., 2020 ). Increased ABA biosynthesis is one of the main plant responses to drought stress ( Soma et al., 2021 ).…”

Effects of Different Chemicals on Sexual Regulation in Persimmon (Diospyros kaki Thunb.) Flowers

“…Sexual reproduction is a key process in the plant life cycle; it is strongly influenced by both genetic and environmental conditions ( Zhu et al, 2020 ). Factors such as drought, temperature, salinity, and phytohormones extensively contribute to plant growth and development, inducing various morphological, physiological, and biochemical responses ( Utsumi et al, 2019 ; Li F. et al, 2020 ). Metabolomics data can connect genomic and phenotypic manifestations ( Xia et al, 2021 ).…”