Salt-alkali stress threatens the resilience to variable environments and thus the grain yield of rice. However, how rice responds to salt-alkali stress at the molecular level is poorly understood. ...Here, we report isolation of a novel salt-alkali-tolerant rice (SATR) by screening more than 700 germplasm accessions. Using 93-11, a widely grown cultivar, as a control, we characterized SATR in response to strong salt-alkali stress (SSAS). SATR exhibited SSAS tolerance higher than 93-11, as indicated by a higher survival rate, associated with higher peroxidase activity and total soluble sugar content but lower malonaldehyde accumulation. A transcriptome study showed that cell wall biogenesis-related pathways were most significantly enriched in SATR relative to 93-11 upon SSAS. Furthermore, higher induction of gene expression in the cell wall matrix polysaccharide biosynthesis pathway, coupled with higher accumulations of hemicellulose and pectin as well as measurable physio-biochemical adaptive responses, may explain the strong SSAS tolerance in SATR. We mapped SSAS tolerance to five genomic regions in which 35 genes were candidates potentially governing SSAS tolerance. The 1,4-β-D-xylan synthase gene
in hemicellulose biosynthesis pathway was investigated in details. The
function-disrupted mutant displayed reduced SSAS tolerance, biomass and grain yield, whereas the
overexpression lines exhibited increased SSAS tolerance. Collectively, this study not only reveals the potential role of cell wall matrix polysaccharides in mediating SSAS tolerance, but also highlights applicable value of
and the large-scale screening system in developing SSAS-tolerant rice.
Abstract
We confirm the planetary nature of two gas giants discovered by TESS to transit M dwarfs with stellar companions at wide separations. TOI-3984 A (
J
= 11.93) is an M4 dwarf hosting a ...short-period (4.353326 ± 0.000005 days) gas giant (
M
p
= 0.14 ± 0.03
M
J
and
R
p
= 0.71 ± 0.02
R
J
) with a wide-separation white dwarf companion. TOI-5293 A (
J
= 12.47) is an M3 dwarf hosting a short-period (2.930289 ± 0.000004 days) gas giant (
M
p
= 0.54 ± 0.07
M
J
and
R
p
= 1.06 ± 0.04
R
J
) with a wide-separation M dwarf companion. We characterize both systems using a combination of ground- and space-based photometry, speckle imaging, and high-precision radial velocities from the Habitable-zone Planet Finder and NEID spectrographs. TOI-3984 A b (
T
eq
= 563 ± 15 K and
TSM
=
138
−
27
+
29
) and TOI-5293 A b (
T
eq
=
675
−
30
+
42
K and TSM = 92 ± 14) are two of the coolest gas giants among the population of hot Jupiter–sized gas planets orbiting M dwarfs and are favorable targets for atmospheric characterization of temperate gas giants and 3D obliquity measurements to probe system architecture and migration scenarios.
Abstract
We report the measurement of the sky-projected obliquity angle
λ
of the warm Jovian exoplanet TOI-1670 c via the Rossiter–McLaughlin effect. We observed the transit window during UT 2023 ...April 20 for 7 continuous hours with NEID on the 3.5 m WIYN Telescope at Kitt Peak National Observatory. TOI-1670 hosts a sub-Neptune (
P
∼ 11 days; planet b) interior to the warm Jovian (
P
∼ 40 days; planet c), which presents an opportunity to investigate the dynamics of a warm Jupiter with an inner companion. Additionally, TOI-1670 c is now among the longest-period planets to date to have its sky-projected obliquity angle measured. We find planet c is well aligned to the host star, with
λ
= − 0.°3 ± 2.°2. TOI-1670 c joins a growing census of aligned warm Jupiters around single stars and aligned planets in multiplanet systems.
The flavonoid compounds are important secondary metabolites with versatile human nutritive benefits and fulfill a multitude of functions during plant growth and development. The abundance of ...different flavonoid compounds are finely tuned with species-specific pattern by a ternary MBW complex, which consists of a MYB, a bHLH, and a WD40 protein, but the essential role of SlAN11, which is a WD40 protein, is not fully understood in tomato until now. In this study, a tomato WD40 protein named as SlAN11 was characterized as an effective transcription regulator to promote plant anthocyanin and seed proanthocyanidin (PA) contents, with late flavonoid biosynthetic genes activated in 35S::SlAN11 transgenic lines, while the dihydroflavonol flow to the accumulation of flavonols or their glycosylated derivatives was reduced by repressing the expression of SlFLS in this SlAN11-overexpressed lines. The above changes were reversed in 35S::SlAN11-RNAi transgenic lines except remained levels of flavonol compounds and SlFLS expression. Interestingly, our data revealed that SlAN11 gene could affect seed dormancy by regulating the expressions of abscisic acid (ABA) signaling-related genes SlABI3 and SlABI5, and the sensitivity to ABA treatment in seed germination is conversely changed by SlAN11-overexpressed or -downregulated lines. Yeast two-hybrid assays demonstrated that SlAN11 interacted with bHLH but not with MYB proteins in the ternary MBW complex, whereas bHLH interacted with MYB in tomato. Our results indicated that low level of anthocyanins in tomato fruits, with low expression of bHLH (SlTT8) and MYB (SlANT1 and SlAN2) genes, remain unchanged upon modification of SlAN11 gene alone in the transgenic lines. These results suggest that the tomato WD40 protein SlAN11, coordinating with bHLH and MYB proteins, plays a crucial role in the fine adjustment of the flavonoid biosynthesis and seed dormancy in tomato.
Kiwifruit (
) is commonly covered by fruit hairs (trichomes) that affect kiwifruit popularity in the commercial market. However, it remains largely unknown which gene mediates trichome development in ...kiwifruit. In this study, we analyzed two kiwifruit species,
(Ae) with long, straight, and bushy trichomes and
(Al) with short, distorted, and spare trichomes, by second- and third-generation RNA sequencing. Transcriptomic analysis indicated that the expression of the
gene, a positive regulator of trichome development, was suppressed in Al compared with that in Ae. Additionally, the alternative splicing of
produced two short transcripts (
and
) lacking multiple exons, in addition to a full-length transcript of
. The defects of trichome development (short and distorted trichome) in
mutant were rescued by
but not by
.
gene does not affect trichome density in
mutant. The qRT-PCR analysis indicated that the alternative splicing further reduces the level of functional transcripts. These results indicated that the short and distorted trichomes in Al might be caused by the suppression and alternative splicing of
. Together, we revealed that
mediates trichome development and is a good candidate target for genetic modification of trichome length in kiwifruit.
Promoters are one of the most critical elements in regulating gene expression. They are considered essential biotechnological tools for heterologous protein production. The one most widely used in ...plants is the
promoter from
. However, our study for the first time discovered the
promoter reduced the expression of exogenous proteins under increased antibiotic stress. We discovered an endogenous strong promoter from duckweed named
that keeps higher initiation activity under antibiotic stress. Stable transformation in duckweed showed that the gene expression of
in the
was 1.76 times that of the
at 100 mg.L
G418 and 6.18 times at 500 mg.L
G418. Notably, with the increase of G418 concentration, the gene expression and the fluorescence signal of
in the
were weakened, while the
only changed slightly. This is because, under high antibiotic stress, the
promoter was methylated, leading to the gene silencing of the
gene. Meanwhile, the
promoter was not methylated and maintained high activity. This is a previously unknown mechanism that provides us with new insights into screening more stable promoters that are less affected by environmental stress. These outcomes suggest that the
promoter has a high capacity to initiate the expression of exogenous proteins. In conclusion, our study provides a promoter tool with potential application for plant genetic engineering and also provides new insights into screening promoters.
Abstract
Warm Jupiters are close-in giant planets with relatively large planet–star separations (i.e., 10 <
a
/
R
⋆
< 100). Given their weak tidal interactions with their host stars, measurements of ...stellar obliquity may be used to probe the initial obliquity distribution and dynamical history for close-in gas giants. Using spectroscopic observations, we confirm the planetary nature of TOI-1859b and determine the stellar obliquity of TOI-1859 to be
λ
= 38.9
−
2.7
+
2.8
° relative to its planetary companion using the Rossiter–McLaughlin effect. TOI-1859b is a 64 day warm Jupiter orbiting around a late F dwarf and has an orbital eccentricity of 0.57
−
0.16
+
0.12
inferred purely from transit light curves. The eccentric and misaligned orbit of TOI-1859b is likely an outcome of dynamical interactions, such as planet–planet scattering and planet–disk resonance crossing.
Fruits are a major source of nutrition in human diets, providing carbohydrates, fiber, vitamins and phytonutrients. Carotenoids are a principal class of compounds found in many fruits, providing ...nutritional benefits both as precursors to essential vitamins and as antioxidants. Molecular characterization revealed that the tomato high pigment mutant genes (hp1 and hp2) encode UV-DAMAGED DNA BINDING PROTEIN-1 (DDB1) and DE-ETIOLATED-1 (DET1) homologs, respectively, and both are essential components of the recently identified CUL4-based E3 ligase complex. Here we have isolated a tomato CUL4 homolog and performed yeast two-hybrid assays to suggest possible association of tomato DDB1 with CUL4 and DET1. Real-time RT-PCR analysis indicated that both HP1 and CUL4 are expressed constitutively. Abscisic acid is implicated in plastid division control and its application substantially enhances HP1/DDB1 mRNA accumulation. Transformation of constructs expressing CUL4-YFP and DDB1-YFP fusion proteins driven by the CaMV 35S promoter reveals that both CUL4 and DDB1 are targeted to tomato plastids and nuclei simultaneously. Using fruit-specific promoters combined with RNAi technology, we show that downregulated DDB1 expression in transgenic fruits results in a significant increase in the number of plastids and corresponding enhanced pigment accumulation. CUL4-RNAi repression lines provide insight regarding CUL4 function during tomato development, and reveal that this tomato cullin is important in the regulation of plastid number and pigmentation, which in turn have a direct impact on fruit nutrient quality.
We present 10 R-band photometric observations of eight different transits of the hot Jupiter HAT-P-33b, which has been targeted by our Transiting Exoplanet Monitoring Project. The data were obtained ...by two telescopes at the Xinglong Station of National Astronomical Observatories of China (NAOC) from 2013 December through 2016 January, and exhibit photometric scatter of . After jointly analyzing the previously published photometric data, radial-velocity (RV) measurements, and our new light curves, we revisit the system parameters and orbital ephemeris for the HAT-P-33b system. Our results are consistent with the published values except for the planet to star radius ratio ( ), the ingress/egress duration (τ) and the total duration (T14), which together indicate a slightly shallower and shorter transit shape. Our results are based on more complete light curves, whereas the previously published work had only one complete transit light curve. No significant anomalies in Transit Timing Variations (TTVs) are found, and we place upper mass limits on potential perturbers, largely supplanting the loose constraints provided by the extant RV data. The TTV limits are stronger near mean-motion resonances, especially for the low-order commensurabilities. We can exclude the existence of a perturber with mass larger than 0.6, 0.3, 0.5, 0.5, and near the 1:3, 1:2, 2:3, 3:2, and 2:1 resonances, respectively.
The widespread prevalence of close-in, nearly coplanar super-Earth- and sub-Neptune-sized planets in multiple-planet systems was one of the most surprising results from the Kepler mission. By ...studying a uniform sample of Kepler "multis" with mass measurements from transit-timing variations, we show that a given planetary system tends to harbor a characteristic type of planet. That is, planets in a system have both masses and radii that are far more similar than if the system were assembled randomly from planets in the population. This finding has two important ramifications. First, the large intrinsic compositional scatter in the planet mass-radius relation is dominated by system-to-system variance rather than intra-system variance. Second, if provided enough properties of the star and primordial protoplanetary disk, there may be a substantial degree of predictability in the outcome of the planet formation process. We show that stellar mass and metallicity account for of order 20% of the variation in outcomes; the remainder is as yet unknown.
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