Search

Tillering is an important agronomic trait essential for the yield of Triticum aestivum and the propagation of Aegilops tauschii. However, the effect of phytohormones on T. aestivum and Ae. tauschii tillering and the underlying regulatory mechanisms remain poorly understood. In the study, we found that T. aestivum and Ae. tauschii exhibited different tillering sensitivities to the auxin herbicide 2,4-D isooctyl ester. At 3 days post-application, tiller bud growth was inhibited by 77.50% in T. aestivum , corresponding to 2.0-fold greater inhibition than that in Ae. tauschii (38.71%). Transcriptome analysis showed that differentially expressed genes (DEGs) in the T. aestivum response to 2,4-D isooctyl ester were mainly enriched in plant hormone metabolism and signal transduction pathways, but similar changes were not observed in Ae. tauschii. Among that, the auxin biosynthesis and signaling induced by 2,4-D isooctyl ester was quite different between the two species. A total of nine candidate genes involved in varied tillering responses were selected from the DEGs and validated by quantitative real-time PCR. Endogenous hormone levels were assayed to further verify the RNA-seq results. After 2,4-D isooctyl ester treatment, a significant increase in abscisic acid (ABA) levels was observed in T. aestivum , whereas ABA levels were relatively stable in Ae. tauschii. The herbicide induced more cytokinin (CTK) accumulation in Ae. tauschii than in T. aestivum. External ABA clearly restricted tiller bud growth in both T. aestivum and Ae. tauschii , while 6-benzyl aminopurine had no significant effect. These results indicate that ABA and CTK may be related with 2,4-D isooctyl ester-regulated tillering differences between the two species, which will help to further understand the mechanism of the auxin-mediated regulation of tillering [ABSTRACT FROM AUTHOR]

Duckweed is a kind of aquatic plant with the characteristics of high nutritional value and medicinal benefits. However, most researches focused on the natural germplasms. The underlying metabolic pathway remains to be systematically elaborated in duckweed. In our laboratory, one reddish-purple mutant with high-flavonoids was screened from a mutant library of Spirodela polyrhiza 6068, named 68-red. The content of anthocyanins and proanthocyanidins in 68-red mutant increased by 563.47% and 231.19%, respectively, compared to wild type. It is interesting that cynaroside and orientin content were significantly increased, in contrast, apigetrin and vitexin were decreased in 68-red mutant. Considering this, metabolome and transcriptome were employed to explore the flavonoids biosynthetic pathway. Here, a total of 734 metabolites were identified in the wild type and 68-red mutant. Among which, cyanidin-3-O-glucoside, cyanidin-3-O-galactoside, pelargonidin-3-O-glucoside and pelargonidin-3-O-(6″-O-malonyl)glucoside were significantly accumulated, which were positively correlated with deep reddish-purple of 68-red mutant. In addition, proanthocyanidins (B1, B2, B3, B4, C1, C2), flavonoid and its glycosides (11 luteolin and its glycosides, 14 quercetin and its glycosides, 14 kaempferol and its glycosides, 2 apigenin glycosides) were significantly accumulated, 2 apigenin glycosides were down-regulated in 68-red mutant. The transcriptome data and qRT-PCR indicated that 16 enzyme genes in flavonoids biosynthetic pathway (PAL , C4H , CHSs , F3H , ANS , ANR , F3′Hs , DFRs , LAR , GT1 , BZ1) were significantly up-regulated in 68-red mutant. Correlation analysis found that three copies of F3′H gene play important roles in the synthesis of anthocyanins, luteolin and apigenin glycosides. In conclusion, the 68-red mutant is a high quality germplasm resources for food and medical industry. Metabolome and transcriptome provide new insight for exploring the enzyme genes and functional metabolites in duckweed. [ABSTRACT FROM AUTHOR]

Tausch's goatgrass (Aegilops tauschii Coss.), is a major weed species, infesting wheat (Triticum aestivum) fields in China. 2,4-D isooctyl ester is widely used for broadleaf weed control and selected as a tool to study the differences between, A. tauschii and T. aestivum. In this study, we measured the growth responses of these species to 2,4-D isooctyl ester and found that T. aestivum was more sensitive to the herbicide than A. tauschii. To clarify the reasons for this difference, we measured the leaf-mediated deposition, absorption and metabolism of 2,4-D isooctyl ester and the expression of auxin receptor transport inhibitor response (TIR1) gene in T. aestivum and A. tauschii. The results indicated that the deposition of 2,4-D isooctyl ester droplets may be lower on A. tauschii than on T. aestivum , because of the increased contact angle and greater density of trichomes on the leaves of the former. A distinct increase in 2,4-D isooctyl ester uptake was detected in T. aestivum during the entire experimental period, and the rate was 2.2-fold greater than that in A. tauschii at 6 h after treatment. Compared with A. tauschii , T. aestivum exhibited a greater accumulation of primary metabolite 2,4-D in plants, which may be responsible for the different responses of the two species. Additionally, the absolute expression level of TIR1 was clearly greater in T. aestivum than that in A. tauschii. These data will be helpful to further understand the differences between T. aestivum and A. tauschii , which may provide a unique perspective for the development and identification of new target compounds that are effective against this weed species. [Display omitted] • Herbicide to control Aegilops tauschii Coss is limited. • Triticum aestivum was more sensitive to 2,4-D isooctyl ester than A. tauschii. • Weak leaf-mediated deposition of 2,4-D isooctyl ester was observed for A. tauschii. • Different uptake and metabolism mediated various sensitivities between two species. • The expression level of TIR1 was higher in T. aestivum than that in A. tauschii. [ABSTRACT FROM AUTHOR]

Wood formation involves sequential developmental events requiring the coordination of multiple hormones. Brassinosteroids (BRs) play a key role in wood development, but little is known about the cellular and molecular processes that underlie wood formation in tree species. Here, we generated transgenic poplar lines with edited PdBRI1 genes, which are orthologs of Arabidopsis vascular-enriched BR receptors, and showed how inhibition of BR signaling influences wood development at the mRNA and/or proteome level. Six Populus PdBRI1 genes formed three gene pairs, each of which was highly expressed in basal stems. Simultaneous mutation of PdBRI1-1, -2, -3 and - 6, which are orthologs of the Arabidopsis vascular-enriched BR receptors BRI1, BRL1 and BRL3, resulted in severe growth defects. In particular, the stems of these mutant lines displayed a discontinuous cambial ring and patterning defects in derived secondary vascular tissues. Abnormal cambial formation within the cortical parenchyma was also observed in the stems of pdbri1-1;2;3;6. Transgenic poplar plants expressing edited versions of PdBRI1-1 or PdBRI1-1;2;6 exhibited phenotypic alterations in stem development at 4.5 months of growth, indicating that there is functional redundancy among these PdBRI1 genes. Integrated analysis of the transcriptome and proteome of pdbri1-1;2;3;6 stems revealed differential expression of a number of genes/proteins associated with wood development and hormones. Concordant (16%) and discordant (84%) regulation of mRNA and protein expression, including wood-associated mRNA/protein expression, was found in pdbri1-1;2;3;6 stems. This study found a dual role of BRs in procambial cell division and xylem differentiation and provides insights into the multiple layers of gene regulation that contribute to wood formation in Populus., (© The Author(s) 2022. Published by Oxford University Press on behalf of Nanjing Agricultural University.)

To investigate the value of hip circumference related indexes for identifying childhood hypertension. In 2011, 1,352 Han children aged 7-12 years were recruited in our study. Hypertension was defined as systolic blood pressure or diastolic blood pressure ≥95th percentile for all three screenings. We set the power value of the hip circumference/height x ratio (x = 0, 0.8, 1 and 1.5) and studied the association with blood pressure. Hip circumference, hip circumference/height 0.8 , hip circumference/height and hip circumference/height 1.5 all showed a positive correlation with systolic blood pressure and diastolic blood pressure(P < 0.05). Area under the curve (AUC) was used to evaluate the abilities of hip circumference related indexes. Hip circumference/height 0.8 , hip circumference/height and hip circumference/height1.5 were not superior to hip circumference. The present study demonstrates that hip circumference measurement is a helpful tool to detect the presence of hypertension in Han children 7-12 years old.