The osmolyte-producing endophyte Streptomyces albidoflavus OsiLf-2 induces drought and salt tolerance in rice via a multi-level mechanism

Drought and salinity are major environmental stresses that impair crop growth and productivity worldwide. Improving drought and salt tolerance of crops with microbial mutualists is an effective and environmentally sound strategy to meet the demands of the ever-growing world population. In the present study, we found that the Streptomyces albidoflavus Osi Lf-2, a moderately salt-tolerant endophytic actinomycete, produced abundant osmolytes, including proline, polysaccharides, and ectoine. Inoculation with Osi Lf-2 increased the osmotic-adjustment ability of the rice host by increasing the proline content(by250.3% and 49.4%) and soluble sugar(by 20.9% and 49.4%) in rice under drought and salt conditions, relative to the uninoculated control. Osi Lf-2 increased stress responses in the rice host at the physiological and biochemical levels(photosynthesis efficiency, osmolytes and antioxidant content), and the gene level(osmolytes synthesis, stress-responsive and ion-transport related genes), raising rice yields under both greenhouse and saline–alkaline soil conditions. The use of endophytic actinomycetes offers a promising biotechnological approach to developing stress-tolerant plants.

Shortened Basal Internodes Encodes a Gibberellin 2-Oxidase and Contributes to Lodging Resistance in Rice

改进住宿抵抗的繁殖半矮子变化被证明了在自从绿 revolution.?However 的来临，增加谷物产量极其成功，在亚洲繁殖半矮子米饭变化的多数主要依赖于 SD1 的变异的等位基因的基因介绍，它编码赤霉素( GA ) 20-oxidase ， OsGA20ox2 ，为催化 GA 生合成。这里，我们报导新米饭住宿抵抗基因，弄短的基础 Internodes (SBI ) ，它编码赤霉素 ? 2-oxidase 并且明确地控制灰煤杆的延伸通过撤销的基础 internodes GA 活动。SBI 主要在灰煤杆被表示基础 internodes。基因分析显示 SBI 是影响米饭高度和住宿抵抗的半主导的基因。SBI 突变而产生之遗传的变体显示不同活动并且与米饭变化的高度被联系。与 SBI 等位基因的更高的活动繁殖与改进住宿抵抗和增加的产量产生新米饭变化。SBI 的发现为生产半矮子米饭显型提供一个理想的基因资源并且为与提高的住宿抵抗和高产量引起米饭变化提供有效策略。

Ectopic expression of fungal EcGDH improves nitrogen assimilation and grain yield in rice

NADP(H)-dependent glutamate dehydrogenases(GDH) in lower organisms have stronger ammonium affinity than those in higher plants. Here we report that transgenic rice overexpressing the EcGDH from Eurotium cheralieri exhibited significantly enhanced aminating activities. Hydroponic and field tests showed that nitrogen assimilation efficiency and grain yields were markedly increased in these transgenic plants, especially at the low nitrogen conditions.These results suggest that EcGDH may have potential to be used to improve nitrogen assimilation and grain yield in rice.

Reproductive tissue-specific translatome of a rice thermo-sensitive genic male sterile line

Translational regulation,especially tissue-or cell type-specific gene regulation,plays essential roles in plant growth and development.Thermo-sensitive genic male sterile(TGMS)lines have been widely used for hybrid breeding in rice(Oryza sativa).However,little is known about translational regulation during reproductive stage in TGMS rice.Here,we use translating ribosome affinity purification(TRAP)combined with RNA sequencing to investigate the reproductive tissue-specific translatome of TGMS rice expressing FLAG-tagged ribosomal protein L18(RPL18)from the germline-specific promoter MEIOSIS ARRESTED AT LEPTOTENE1(MEL1).Differentially expressed genes at the transcriptional and translational levels are enriched in pollen and anther-related formation and development processes.These contain a number of genes reported to be involved in tapetum programmed cell death(PCD)and lipid metabolism during pollen development and anther dehiscence in rice,including several encoding transcription factors and key enzymes,as well as several long non-coding RNAs(lnc RNAs)that potentially affect tapetum and pollenrelated genes in male sterility.This study represents the comprehensive reproductive tissue-specific characterization of the translatome in TGMS rice.These results contribute to our understanding of the molecular basis of sterility in TGMS rice and will facilitate further genetic manipulation of TGMS rice in two-line breeding systems.

Characterization of grain cadmium concentration in indica hybrid rice

As a consequence of contamination of soil with heavy metals,cadmium accumulation in grain is of great concern worldwide,but especially in southern China.It is important to evaluate the Cd accumulation potential of grain before or when examining and approving new cultivars.An evaluation method and criteria for verifying Cd accumulation potential in rice are proposed,and the Cd accumulation potential of 56 mid-season indica hybrids collected from the provincial cultivar trials in 2016 were investigated.Genotype,environment and their interactions strongly affected the variation in grain Cd accumulation.Two hybrids were identified as slightly Cd accumulating.Hybrids with slight Cd accumulation potential would be suitable for safe grain production on polluted land(total Cd under 2.0 mg$kg–1)in Hunan Province(China)and should be considered for new cultivar evaluation and approval.This evaluation method and criterion could be applied for certifying Cd accumulation potential of rice cultivars.