6 research outputs found
Effects of elevated atmospheric [CO2] on grain starch characteristics in different specialized wheat
The increasing atmospheric [CO2] poses great challenges to wheat production. Currently, the response of starch characteristics in different specialized wheat cultivars to elevated [CO2], as well as the underlying physiological and molecular mechanisms remains unclear. Therefore, an experiment was conducted with open-top chambers to study the effects of ambient [CO2] [a(CO2)] and elevated [CO2] [e(CO2)] on photosynthetic performance, yield and starch characteristics of bread wheat (Zhengmai 369, ZM369) and biscuit wheat (Yangmai 15, YM15) from 2020 to 2022. The results demonstrated a significant improvement in photosynthetic performance, yield, amylose and amylopectin content, volume ratio of large granules under e[CO2]. Moreover, e[CO2] upregulated the gene expression and enzyme activities of GBSS (Granule-bound starch synthase) and SSS (Soluble starch synthase), increased starch pasting viscosity, gelatinization enthalpy and crystallinity. Compared to YM15, ZM369 exhibited a higher upregulation of GBSSI, greater increase in amylose content and volume ratio of large granules, as well as higher gelatinization enthalpy and crystallinity. However, ZM369 showed a lower increase in amylopectin content and a lower upregulation of SSSI and SSSII. Correlation analysis revealed amylose and amylopectin content had a positive correlation with GBSS and SSS, respectively, a significant positively correlation among the amylose and amylopectin content, starch granule volume, and pasting properties. In conclusion, these changes may enhance the utilization value of biscuit wheat but exhibit an opposite effect on bread wheat. The results provide a basis for selecting suitable wheat cultivars and ensuring food security under future climate change conditions
Variation in Leaf Type, Canopy Architecture, and Light and Nitrogen Distribution Characteristics of Two Winter Wheat (Triticum aestivum L.) Varieties with High Nitrogen-Use Efficiency
Studies of traits related to nitrogen (N)-use efficiency (NUE) in wheat cultivars are important for breeding N-efficient cultivars. Canopy structure has a major effect on NUE, as it determines the distribution of light and N. However, the mechanism by which canopy structure affects the distribution of light and N within the canopy remains unclear. The N-efficient winter wheat varieties YM49 and ZM27 and N-inefficient winter wheat varieties XN509 and AK58 were grown in the field under two N levels. Light transmittance was enhanced, and the leaf area index and photosynthetically active radiation were lower in the N-efficient cultivar population, which was characterized by moderately sized flag leaves, a low frequency of canopy leaf curling, a low light attenuation coefficient (KL), and high plant compactness. Reductions in the amount of shade increased the distribution of light and N resources to the middle and lower layers. The photosynthetic rate, transpiration rate, instant water-use efficiency, and canopy photosynthetic NUE were higher, N remobilization of the upper and middle canopy leaves was reduced, and the leaf N content was high in the N-efficient cultivars. A higher ratio of the N extinction coefficient (KN) to KL reflects the assimilation ability of the N-efficient winter wheat cultivars, resulting in improved canopy structure and distribution of light and N, higher 1000-grain weight and grain yield, and significantly increased light and NUE. An improved match between gradients of light and N in the leaf canopy promotes balanced C and N metabolism and reduces energy and nutrient losses. This should be a goal when breeding N-efficient wheat cultivars and implementing tillage regimes
Synergistic Therapy of Doxorubicin and miR-129-5p with Self-Cross-Linked Bioreducible Polypeptide Nanoparticles Reverses Multidrug Resistance in Cancer Cells
Although
microRNAs (miRs) are short endogenous noncoding RNAs playing
a central role in cancer initiation and progression, their therapeutic
potential in overcoming multidrug resistance (MDR) remains unclear.
In the present study, we developed self-cross-linked biodegradable
poly(ethylene glycol)-<i>b</i>-poly(l-lysine)-<i>b</i>-poly(l-cysteine) (LCss) polypeptide nanoparticles
to codeliver DOX and miR-129-5p, which aimed to overcome MDR in cancer
cells. The results showed that LCss nanoparticles effectively coencapsulated
DOX and miR with great stability, but quickly disassembled and released
their payload in a bioreducible environment. The codelivery of miR-129-5p
and DOX with LCss (DLCss/miR) significantly increased miR-129-5p expression
over 100-fold in MCF-7/ADR cells, which effectively overcame MDR by
directly inhibiting P-glycoprotein (P-gp), thereby increasing intracellular
DOX accumulation and cytotoxicity in MCF-7/ADR cells. Furthermore,
miR-129-5p also partially diminished cyclin-dependent kinase 6 (CDK6),
and synergized with DOX to simultaneously decrease S phase and induce
G<sub>2</sub> phase cell cycle arrest, thereby further enhancing the
chemosensitivity of MCF-7/ADR cells. Hence, redox-responsive LCss
nanoparticles are potent nanocarrier for combinational drug-miR therapy,
which could be a promising strategy to overcome MDR in cancer cells
Integrated Nanovaccine with MicroRNA-148a Inhibition Reprograms Tumor-Associated Dendritic Cells by Modulating miR-148a/DNMT1/SOCS1 Axis
ROS-Inducing Micelles Sensitize Tumor-Associated Macrophages to TLR3 Stimulation for Potent Immunotherapy
One
approach to cancer immunotherapy is the repolarization of immunosuppressive
tumor-associated macrophages (TAMs) to antitumor M1 macrophages. The
present study developed galactose-functionalized zinc protoporphyrin
IX (ZnPP) grafted poly(l-lysine)-<i>b</i>-poly(ethylene
glycol) polypeptide micelles (ZnPP PM) for TAM-targeted immunopotentiator
delivery, which aimed at in vivo repolarization of TAMs to antitumor
M1 macrophages. The outcomes revealed that ROS-inducing ZnPP PM demonstrated
specificity for the in vitro and in vivo targeting of macrophages,
elevated the level of ROS, and lowered STAT3 expression in BM-TAMs.
Poly I:C (PIC, a TLR3 agonist)-loaded ZnPP PM (ZnPP PM/PIC) efficiently
repolarized TAMs to M1 macrophages, which were reliant on ROS generation.
Further, ZnPP PM/PIC substantially elevated the activated NK cells
and T lymphocytes in B16–F10 melanoma tumors, which caused
vigorous tumor regression. Therefore, the TAM-targeted transport of
an immunologic adjuvant with ZnPP-grafted nanovectors may be a potential
strategy to repolarize TAMs to M1 macrophages in situ for effective
cancer immunotherapy
DataSheet_1_Effects of elevated atmospheric [CO2] on grain starch characteristics in different specialized wheat.docx
The increasing atmospheric [CO2] poses great challenges to wheat production. Currently, the response of starch characteristics in different specialized wheat cultivars to elevated [CO2], as well as the underlying physiological and molecular mechanisms remains unclear. Therefore, an experiment was conducted with open-top chambers to study the effects of ambient [CO2] [a(CO2)] and elevated [CO2] [e(CO2)] on photosynthetic performance, yield and starch characteristics of bread wheat (Zhengmai 369, ZM369) and biscuit wheat (Yangmai 15, YM15) from 2020 to 2022. The results demonstrated a significant improvement in photosynthetic performance, yield, amylose and amylopectin content, volume ratio of large granules under e[CO2]. Moreover, e[CO2] upregulated the gene expression and enzyme activities of GBSS (Granule-bound starch synthase) and SSS (Soluble starch synthase), increased starch pasting viscosity, gelatinization enthalpy and crystallinity. Compared to YM15, ZM369 exhibited a higher upregulation of GBSSI, greater increase in amylose content and volume ratio of large granules, as well as higher gelatinization enthalpy and crystallinity. However, ZM369 showed a lower increase in amylopectin content and a lower upregulation of SSSI and SSSII. Correlation analysis revealed amylose and amylopectin content had a positive correlation with GBSS and SSS, respectively, a significant positively correlation among the amylose and amylopectin content, starch granule volume, and pasting properties. In conclusion, these changes may enhance the utilization value of biscuit wheat but exhibit an opposite effect on bread wheat. The results provide a basis for selecting suitable wheat cultivars and ensuring food security under future climate change conditions.</p