A Novel LncRNA, MuLnc1, Associated With Environmental Stress in Mulberry (Morus multicaulis)

Abstract

Environmental stresses are major constraints that limit the leaf productivity and quality of mulberry. LncRNAs have emerged as important regulators in response to biotic and abiotic stresses in plants. However, the functions and mechanisms of most lncRNAs remain largely unknown. A novel lncRNA designated as MuLnc1 was found to be cleaved by mul-miR3954 and produce secondary siRNAs in a 21 nt phase in mulberry. It was demonstrated that one of the siRNAs produced, si161579, can silence the expression of the calmodulin-like protein gene CML27 of mulberry (MuCML27). When MuCML27 was heterologously expressed in Arabidopsis, the transgenic plants exhibited enhanced resistance to Botrytis cinerea and Pseudomonas syringae pv tomato DC3000. In addition, the transgenic MuCML27-overexpressing Arabidopsis plants are more tolerant to salt and drought stresses. Furthermore, the network of mul-miR3954-MuLnc1-siRNAs-mRNAs was modeled to elucidate the interaction between lncRNAs and sRNAs with mRNAs. All of these, taken together, suggest that MuLnc1 was associated with environmental stress in mulberry and may be considered as a potential genetic improvement target gene of mulberry. The information provided may shed light on the complicated gene expression regulatory mechanisms in mulberry stress responses.

Cell Wall Bulking by Maleic Anhydride for Wood Durability Improvement

“…Compared with the previously reported methods which mainly referred to physically filling the dynamic nanopores or chemically bonding to the hydroxyl groups, the strategy proposed in this study is a dual modification method, that is, the use of maleic anhydride (MAn) to improve wood durability (i.e., dimensional stability and decay resistance) via dynamic nanopore filling combined with hydroxyl group elimination. Although acetic anhydride, melamine formaldehyde, sorbitol, and N-methylol melamine have been reported to modify the cell wall for durability improvement in a similar strategy to our work, several drawbacks like the strong acid catalysts employed or formaldehyde release adversely affect their properties and the environment, and thus limit their practical applications [39][40][41][42][43]. Although maleic anhydride was reported to bulk the cell wall and chemically bond to the hydroxyl group, the employed methods still use solvents like DMSO, which are difficult to remove after the reaction, and the vapor phase reaction requires specific equipment [44][45][46].…”

Mechanisms and Functions of Long Non-Coding RNAs at Multiple Regulatory Levels

“…In addition to si161579, the siRNAs derived from MuLnc1 have also been predicted to target many protein-coding genes with different functions. Therefore, as a precursor of these siRNAs, the lncRNA MuLnc1 may be involved in the response to multiple biotic and abiotic stresses [91].…”

Long Non-Coding RNAs, the Dark Matter: An Emerging Regulatory Component in Plants

“…Among these, trans-acting small interfering RNAs (tasiRNAs) or phased secondary small interfering RNAs (phasiRNAs) are two endogenous classes of siRNAs [ 85 , 86 ]. Recently, various studies on lncRNA-derived siRNA havce been reported; among these, the miR390- TAS3 -ARF pathway [ 87 ], the miR3954-lncRNA-phasiRNA-NAC pathway [ 88 ], the mul-miR3954- MuLnc1 -si161579- MuCML27 [ 89 ], and miR2118- PMS1T -phasiRNAs [ 90 ] are well known in various plant species. For instance, a novel lncRNA, MuLnc1 , was targeted by miR3954 to produce 21 nt phasiRNAs in mulberries.…”