Abstract
Nitrogen (N) is indispensable for crop growth and yield, but excessive agricultural application of nitrogenous fertilizers has generated severe environmental problems. A desirable and ...economical solution to cope with these issues is to improve crop nitrogen use efficiency (NUE). Plant NUE has been a focal point of intensive research worldwide, yet much still has to be learned about its genetic determinants and regulation. Here, we show that rice (Oryza sativa L.) NIN-LIKE PROTEIN 1 (OsNLP1) plays a fundamental role in N utilization. OsNLP1 protein localizes in the nucleus and its transcript level is rapidly induced by N starvation. Overexpression of OsNLP1 improves plant growth, grain yield, and NUE under different N conditions, while knockout of OsNLP1 impairs grain yield and NUE under N-limiting conditions. OsNLP1 regulates nitrate and ammonium utilization by cooperatively orchestrating multiple N uptake and assimilation genes. Chromatin immunoprecipitation and yeast one-hybrid assays showed that OsNLP1 can directly bind to the promoter of these genes to activate their expression. Therefore, our results demonstrate that OsNLP1 is a key regulator of N utilization and represents a potential target for improving NUE and yield in rice.
OsNLP1 rapidly responds to N availability, enhances N uptake and assimilation, providing great potential for breeding rice cultivars with high yield and NUE under N-limiting conditions
Salt stress significantly influences plant growth and reduces crop yield. It is highly anticipated to develop salt-tolerant crops with salt tolerance genes and transgenic technology. Hence, it is ...critical to identify salt tolerance genes that can be used to improve crop salt tolerance.
We report that the transcription elongation factor suppressor of Ty 4-2 (SPT4-2) is a positive modulator of salt tolerance in Arabidopsis thaliana. AtSPT4-2 expression is induced by salt stress. Knockout mutants of AtSPT4-2 display a salt-sensitive phenotype, whereas AtSPT4-2 overexpression lines exhibit enhanced salt tolerance. Comparative transcriptomic analyses revealed that AtSPT4-2 may orchestrate the expression of genes associated with salt tolerance, including stress-responsive markers, protein kinases and phosphatases, salt-responsive transcription factors and those maintaining ion homeostasis, suggesting that AtSPT4-2 improves salt tolerance mainly by maintaining ion homeostasis and enhancing stress tolerance.
AtSPT4-2 positively modulates salt tolerance by maintaining ion homeostasis and regulating stress-responsive genes and serves as a candidate for the improvement of crop salt tolerance.
Summary
Nitrogen (N) is one of the key essential macronutrients that affects rice growth and yield. Inorganic N fertilizers are excessively used to boost yield and generate serious collateral ...environmental pollution. Therefore, improving crop N use efficiency (NUE) is highly desirable and has been a major endeavour in crop improvement. However, only a few regulators have been identified that can be used to improve NUE in rice to date. Here we show that the rice NIN‐like protein 4 (OsNLP4) significantly improves the rice NUE and yield. Field trials consistently showed that loss‐of‐OsNLP4 dramatically reduced yield and NUE compared with wild type under different N regimes. In contrast, the OsNLP4 overexpression lines remarkably increased yield by 30% and NUE by 47% under moderate N level compared with wild type. Transcriptomic analyses revealed that OsNLP4 orchestrates the expression of a majority of known N uptake, assimilation and signalling genes by directly binding to the nitrate‐responsive cis‐element in their promoters to regulate their expression. Moreover, overexpression of OsNLP4 can recover the phenotype of Arabidopsis nlp7 mutant and enhance its biomass. Our results demonstrate that OsNLP4 plays a pivotal role in rice NUE and sheds light on crop NUE improvement.
Phosphatidic acid (PA) is an important signal molecule in various biological processes including osmotic stress. Lysophosphatidic acid acyltransferase (LPAT) acylates the sn-2 position of the ...glycerol backbone of lysophosphatidic acid (LPA) to produce PA. The role of LPAT2 and its PA in osmotic stress response remains elusive in plants. Here we showed that LPAT2-derived PA is important for salt and drought stress tolerance in rice. Rice LPAT2 was localized to the endoplasmic reticulum (ER) to catalyze the PA synthesis. The LPAT2 transcript was induced by osmotic stress such as high salinity and water deficit. To reveal its role in osmotic stress response, an LPAT2 knockdown mutant, designated lpat2, was isolated from rice, which contained a reduced PA level relative to wild type (WT) plants under salt stress and water deficit. The lpat2 mutant was more susceptible to osmotic stress and less sensitive to abscisic acid (ABA) than that of WT, which was recovered by either PA supplementation or genetic LPAT2 complementation. Moreover, suppressed LPAT2 also led to a large number of differentially expressed genes (DEGs) involved in diverse processes, particularly, in ABA response, kinase signaling, and ion homeostasis in response to salt stress. Together, LPAT2-produced PA plays a positive role in osmotic tolerance through mediating ABA response, which leads to transcriptional alteration of genes related to ABA response, protein kinase signaling, and ion homeostasis.
Plastid-localized glycerol-3-phosphate acyltransferase (ATS1) catalyzes the first-step reaction in glycerolipid assembly through transferring an acyl moiety to glycerol-3-phosphate (G3P) to generate ...lysophosphatidic acid (LPA), an intermediate in lipid metabolism. The effect of ATS1 overexpression on glycerolipid metabolism and growth remained to be elucidated in plants, particularly oil crop plants. Here, we found that overexpression of
from
enhanced plant growth and prokaryotic glycerolipid biosynthesis. BnATS1 is localized in chloroplasts and an in vitro assay showed that BnATS1 had acylation activity toward glycerol 3-phosphate to produce LPA. Lipid profiling showed that overexpression of
led to increases in multiple glycerolipids including phosphatidylglycerol (PG), monogalactosyldiacylglycerol (MGDG), phosphatidylcholine (PC), and phosphatidylinositol (PI), with increased polyunsaturated fatty acids. Moreover, increased MGDG was attributed to the elevation of 34:6- and 34:5-MGDG, which were derived from the prokaryotic pathway. These results suggest that BnATS1 promotes accumulation of polyunsaturated fatty acids in cellular membranes, thus enhances plant growth under low-temperature conditions in
.
Abstract
Background
Gossypium hirsutum
(upland cotton) is one of the principal fiber crops in the world. Cotton yield is highly affected by abiotic stresses, among which salt stress is considered as ...a major problem around the globe. Transgenic approach is efficient to improve cotton salt tolerance but depending on the availability of salt tolerance genes.
Results
In this study we evaluated salt tolerance candidate gene
ST7
from
Thellungiella halophila
, encoding a homolog of
Arabidopsis
aluminum-induced protein, in cotton. Our results showed that
ThST7
overexpression in cotton improved germination under NaCl stress as well as seedling growth. Our field trials also showed that
ThST7
transgenic cotton lines produced higher yield under salt stress conditions. The improved salt tolerance of the transgenic cotton lines was partially contributed by enhanced antioxidation as shown by diaminobenzidine (DAB) and nitrotetrazolium blue chloride (NBT) staining. Moreover, transcriptomic analysis of
ThST7
overexpression lines showed a significant upregulation of the genes involved in ion homeostasis and antioxidation, consistent with the salt tolerance phenotype of the transgenic cotton.
Conclusions
Our results demonstrate that
ThST7
has the ability to improve salt tolerance in cotton. The
ThST7
transgenic cotton may be used in cotton breeding for salt tolerance cultivars.
Paraquat (PQ) is the third most used broad-spectrum nonselective herbicide around the globe after glyphosate and glufosinate. Repeated usage and overreliance on this herbicide have resulted in the ...emergence of PQ-resistant weeds that are a potential hazard to agriculture. It is generally believed that PQ resistance in weeds is due to increased sequestration of the herbicide and its decreased translocation to the target site, as well as an enhanced ability to scavenge reactive oxygen species. However, little is known about the genetic bases and molecular mechanisms of PQ resistance in weeds, and hence no PQ-resistant crops have been developed to date. Forward genetics of the model plant Arabidopsis thaliana has advanced our understanding of the molecular mechanisms of PQ resistance. This review focuses on PQ resistance loci and resistance mechanisms revealed in Arabidopsis and examines the possibility of developing PQ-resistant crops using the elucidated mechanisms.
This article reviews our current understanding of paraquat resistance mechanisms in weeds and Arabidopsis thaliana and discusses their potential application to the development of paraquat-resistant crops.
Abstract
Background
Salinity is a major abiotic stress to global agriculture which hampers crop growth and development, and eventually reduces yield. Transgenic technology is an effective and ...efficient approach to improve crop salt tolerance but depending on the availability of effective genes. We previously isolated
Salt Tolerance5
(
ThST5
) from the halophyte
Thellungiella halophila
, an ortholog of Arabidopsis
SPT4-2
which encodes a transcription elongation factor. However,
SPT4-2
-confered salt tolerance has not been evaluated in crops yet. Here we report the evaluation of
ThST5
-conferred salt tolerance in cotton (
Gossypium hirsutum
L.).
Results
The
ThST5
overexpression transgenic cotton plants displayed enhanced tolerance to salt stress during seed germination and seedling stage compared with wild type. Particularly, the transgenic plants showed improved salinity tolerance as well as yield under saline field conditions. Comparative transcriptomic analysis showed that
ThST5
improved salt tolerance of transgenic cotton mainly by maintaining ion homeostasis. In addition,
ThST5
also orchestrated the expression of genes encoding antioxidants and salt-responsive transcription factors.
Conclusion
Our results demonstrate that
ThST5
is a promising candidate to improve salt tolerance in cotton.
Abstract
Background
Cotton (
Gossypium hirsutum
), the major textile fiber crop of the world, is negatively affected by salinity. It leads to the induction of adverse effects on growth and ...development of cotton. The overall yield of cotton faces major drawback once they are grown in saline soil. To improve cotton salt tolerance, transgenic approach offers a fast and effective way but it relies on the availability of salt tolerance genes.
Results
In this study, we have reported the evaluation of
ThST103
, a homologue of
Arabidopsis
ozone-induced protein (
AtOZI1
) in
Thellungiella halophila
, in enhancing salt tolerance in cotton
.
Overexpression of
ThST103
enabled cotton plants to germinate and grow better than the wild types under salt stress. The transgenic lines showed enhanced survival rate in the saline environment and experienced less oxidative damage compared with the wild types. In the field, the transgenic cotton lines produced higher yield than the wild type in saline soil. Transcriptomic comparison analyses of
ThST103
overexpression lines versus the wild type revealed upregulated genes enriched in salt stress tolerance and ion homeostasis.
Conclusions
Our results demonstrate that
ThST103
has the capability to improve salt tolerance in cotton. It can be used in cotton breeding for salt tolerance cultivars.
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