Hedychium gardnerianum (kahili ginger).

Native to the Eastern Himalayas, H. gardnerianum has been widely introduced as an ornamental in different regions of the world. It continues to be available as an ornamental and is therefore likely to spread further.H. gardnerianum is an ecologically versatile plant with rapid vegetative growth, the dense rhizome system of the plant prevents regeneration of other species. This very aggressive, shade-tolerant plant is able to form dense thickets on undisturbed sites in the understorey of open and closed-canopy native rain forests and managed forests, as well as in open areas (forest margins, ravines or path sides). Its high seed production and efficient dispersal by rats and birds, allows it to persist in invaded areas for a long time and establish new points of invasion. As H. gardnerianum is able to invade native forests, ecological, conservation and cultural values are threatened and it is a major threat to native biodiversity.

Lcsain3, A Novel Gene From Sheepgrass, Regulates Arabidopsis Seed Germination And Seedling Growth Under Salt Stress

Sheepgrass is a perennial native grass species with an aggressive and vigorous rhizome system, and it can tolerate high levels of salt stress. Many salt stress-responsive genes have been identified in sheepgrass. Here, we identified and characterized a novel salt-induced gene, LcSAIN3 (Leymus chinensis salt-induced 3), from sheepgrass. Expression analysis confirmed that LcSAIN3 is induced by PEG, ABA and salt stress. Subcellular localization analysis indicated that the LcSAIN3 protein is mainly localized in the chloroplasts. The heterologous of LcSAIN3 in Arabidopsis increases seed germination under various stress conditions. More importantly, the seedling survival, plant height and weight of the transgenic plants are higher than those of the WT plants under salt stress. The overexpression of LcSAIN3 causes a relatively high accumulation of free proline; enhances SOD activity; and leads to the upregulated expression of several stress-responsive genes, such as AtRAB26, AtRD29B, AtSOS1 and AtP5CS1. Our results suggest that LcSAIN3 may be a useful gene for the molecular breeding to improve plants salt stress tolerance.

Revealing the full-length transcriptome of caucasian clover rhizome development

Background Caucasian clover (Trifolium ambiguum M. Bieb.) is a strongly rhizomatous, low-crowned perennial leguminous and ground-covering grass. The species may be used as an ornamental plant and is resistant to cold, arid temperatures and grazing due to a well-developed underground rhizome system and a strong clonal reproduction capacity. However, the posttranscriptional mechanism of the development of the rhizome system in caucasian clover has not been comprehensively studied. Additionally, a reference genome for this species has not yet been published, which limits further exploration of many important biological processes in this plant. Result We adopted PacBio sequencing and Illumina sequencing to identify differentially expressed genes (DEGs) in five tissues, including taproot (T1), horizontal rhizome (T2), swelling of taproot (T3), rhizome bud (T4) and rhizome bud tip (T5) tissues, in the caucasian clover rhizome. In total, we obtained 19.82 GB clean data and 80,654 nonredundant transcripts were analysed. Additionally, we identified 78,209 open reading frames (ORFs), 65,227 coding sequences (CDSs), 58,276 simple sequence repeats (SSRs), 6821 alternative splicing (AS) events, 2429 long noncoding RNAs (lncRNAs) and 4501 putative transcription factors (TFs) from 64 different families. Compared with other tissues, T5 exhibited more DEGs, and co-upregulated genes in T5 are mainly annotated as involved in phenylpropanoid biosynthesis. We also identified betaine aldehyde dehydrogenase (BADH) as a highly expressed gene-specific to T5. A weighted gene co-expression network analysis (WGCNA) of transcription factors and physiological indicators were combined to reveal 11 hub genes (MEgreen-GA3), three of which belong to the HB-KNOX family, that are up-regulated in T3. We analysed 276 DEGs involved in hormone signalling and transduction, and the largest number of genes are associated with the auxin (IAA) signalling pathway, with significant up-regulation in T2 and T5. Conclusions This study contributes to our understanding of gene expression across five different tissues and provides preliminary insight into rhizome growth and development in caucasian clover.

Morphology and symmetry of the vegetative parts of Smilax auriculata (Smilacaceae)

Smilax auriculata produces a subterranean rhizome system and an aerial vegetative branching system. Three intergrading types of stems (types 1, 2, and 3) compose the aerial branching system; these types are identified primarily according to prickle concentration, but also differ from one another in additional ways. Type-3 stems are determinate and either proleptic or precocious. Between growing seasons a foliage leaf of a type-3 stem may subtend either a solitary vegetative bud (or an expanded vegetative branch) or an inflorescence superposed over a vegetative bud (or expanded vegetative branch). Occasionally, an inflorescence terminates a type-3 stem. Whereas, rhizomes exhibit solely scale leaves, the aerial vegetative branching system manifests scale leaves, transitional leaves, and foliage leaves. On many type-3 stems the foliage leaves become oriented skyward, by bending of their leaf sheaths and petioles. The aerial vegetative branching system manifests bilateral symmetry and mirror-image symmetry. The inflorescence is a pedunculate umbel. The peduncle culminates in a torus which bears a peripheral whorl of bracts, centripetally situated bracteoles, and pedicellate flowers. Type-1 stems exhibit numerous prickles, which vary from unbranched to branched and from solitary to basally connate in rows.

Revealing the full-length transcriptome of caucasian clover rhizome development

Background: Caucasian clover (Trifolium ambiguum M. Bieb.) is a strongly rhizomatous, low-crowned perennial leguminous and ground-covering grass. The species may be used as an ornamental plant and is resistant to cold, arid temperatures and grazing due to a well-developed underground rhizome system and a strong clonal reproduction capacity. However, the posttranscriptional mechanism of the development of the rhizome system in caucasian clover has not been comprehensively studied. Additionally, a reference genome for this species has not yet been published, which limits further exploration of many important biological processes in this plant. Result: We adopted PacBio Sequencing and Illumina Sequencing to identify differentially expressed transcripts in five tissues taproot (T1), horizontal rhizome (T2), swelling of taproot (T3), rhizome bud (T4) and rhizome bud tip (T5) of the caucasian clover rhizome. In total, we obtained 19.82 GB clean data and 80,654 nonredundant transcripts were analysed. Additionally, we identified 78,209 open reading frames (ORFs), 65,227 coding sequences (CDSs), 58,276 simple sequence repeats (SSRs), 6,821 alternative splicing (AS) sites, 24,29 long noncoding RNAs (lncRNAs) and 4,501 putative transcription factors (TFs) from 64 different families. Compared with other tissues, T5 exhibited more differentially expressed genes, and co-upregulated genes in T5 are mainly annotated as involved in phenylpropanoid biosynthesis. We also identified betaine aldehyde dehydrogenase (BADH) as a highly expressed gene-specific to T5. A weighted gene co-expression network analysis (WGCNA) cluster analysis of transcription factors and physiological indicators were combined to reveal 11 candidate genes (MEgreen-GA3), three of which belong to the HB-KNOX family, that are up-regulated in T3. We analysed 276 differential transcripts involved in hormone signaling and transduction, and the largest number of transcripts are associated with the IAA signaling pathway, with significant up-regulation in T2 and T5. Conclusions: Taken together, this study contributes to our understanding of gene expression across five different tissues and provides preliminary insight into rhizome growth and development in caucasian clover.

Revealing the full-length transcriptome of caucasian clover rhizome development

Background: Caucasian clover (Trifolium ambiguum M.Bieb.) is a strongly rhizomatous, low-crowned perennial leguminous and ground-covering grass. The species may be used as an ornamental plant and is resistant to cold, arid temperatures and grazing due to a well-developed underground rhizome system and a strong clonal reproduction capacity. However, the posttranscriptional mechanism of the development of the rhizome system in caucasian clover has not been comprehensively studied. Additionally, a reference genome for this species has not yet been published, which limits further exploration of many important biological processes in this plant. Result: We adopted PacBio Sequencing and Illumina Sequencing to identify differentially expressed transcripts in five tissues taproot (T1), horizontal rhizome (T2), swelling of taproot (T3), rhizome bud (T4) and rhizome bud tip (T5) of the caucasian clover rhizome. In total, we obtained 19.82 GB clean data and 80,654 nonredundant transcripts were analyzed. Additionally, we identified 78,209 open reading frames (ORFs), 65,227 coding sequences (CDSs), 58,276 simple sequence repeats (SSRs), 6,821 alternative splicing (AS) sites, 24,29 long noncoding RNAs (lncRNAs) and 4,501 putative transcription factors (TFs)from 64 different families. Compared with other tissues, T5 exhibited more differentially expressed genes, and co-upregulated genes in T5 are mainly annotated as involved in phenylpropanoid biosynthesis. We also identified betaine aldehyde dehydrogenase (BADH) as a highly expressed gene specific to T5. WGCNA cluster analysis of transcription factors and physiological indicators were combined to reveal 11 candidate genes (MEgreen-GA3), three of which belong to the HB-KNOX family, that are up-regulated in T3. We analyzed 276 differential transcripts involved in hormone signaling and transduction, and the largest number of transcripts are associated with the IAA signaling pathway, with significant upregulation in T2 and T5. Conclusions: Taken together, this study contributes to our understanding of gene expression across five different tissues and provides preliminary insight into rhizome growth and development in caucasian clover.

The role of bud bank in glyphosate tolerance of two herbaceous species

Background and aims: Commelina erecta and Eutsachys retusa are two perennial weeds, which show high resprouting after glyphosate application. This behavior represents a serious problem for weed management. The purpose of this study was to characterize the bud bank of both species and to assess their response to glyphosate application. M&M: We analyzed 120 reproductive shoots of C. erecta, and 80 reproductive shoots of E. retusa, at 30- and 60-days post- herbicide application. The doses applied to C. erecta were 0 (control), 1.200 and 2.400 g a.i. ha -1 , and to E. retusa were 0 (control), 480 and 1200 g a.i. ha -1 . Results: We found that both species presented active buds in approximately 50% of their nodes, even after herbicide application. Bud bank dynamics changed in both weeds after herbicide application, and therefore their growth pattern. The activation of originally inhibited buds allowed weeds to regrow and survive after glyphosate application altering their architecture. Conclusions: The bud bank plays an important role in glyphosate tolerance in both weeds. The resprouting capacity in both species was similar for any dose of glyphosate applied. Therefore, an alternative control strategy based on the increase of the dose of herbicide would not be a successful alternative for the management of these weeds. The interruption of the storage of reserves in the rhizome system and the reduction of the number of buds would be key to effective long-term management of these and other perennial weeds in no tillage cropping system.

Physiological basis of effective controlling Torpedo grass (Panicum repens L.)

Torpedo grass (Panicum repens L.) is a C4 plant species, present on different soil types. The rhizome system and tubers of grass well developed, although flowering but not yet recorded the presence of seeds and seedlings (Yêu cầu tác giả viết lại toàn bộ câu này, không thể sửa được. Lưu ý câu phải có động từ chính). Tuber has high drought tolerance. Regenerative ability of the grass decreases with water content of the tuber. Tuber inability to regenerate shoots when it has water less than 30% of water at first. Repeatedly cut grass will take the tuber reserve depletion, not sufficient to provide for the regeneration bud sprouts. Coordinate disposal of mowing and using systemic herbicides will lead to better results. 6-8 weeks after cutting, the grass grow well with multiple shoots, spraying glyphosate 480 SL or glyphosate trimethyl sulphonium (GTS) at doses of 6-8 l / ha, mixed with urea at concentrations from 1% to 1.5%. This way helps prevent the emergence of shoots from rhizomes and tubers.