**7.2. Role in alternate splicing**

breeding processes. lncRNAs are known to induce photoperiod-sensitive genetic male sterility (PSMF) in *O. sativa* [82, 86], but the mechanism is not completely well understood. But according to the available reports, two different mechanisms of lncRNA can be possible [23]. In one mechanism, the high expression of the *long day* (*LD*)*-specific male-fertility-associated RNA* (*LDMAR*), a type of lncRNA, is important for the fertility of rice plant during long day (LD) conditions. During male sterility, the programme cell death (PCD) of anther cells occur due to lowered expression of *LDMAR* under LD conditions. The reduced expression of *LDMAR* is mediated by over expressing psi-LDMAR (a siRNA), transcribed in the promoter region of *LDMAR*. Enhanced expression of Psi-LDMAR caused methylation in promoter region through RdDM mechanism [81]. The other mechanism suggested the involvement of osa-sm R5864w (a 21-nt sRNA) which was formed from a unique ncRNA encoded by *LDMAR*. The

**Biological role Regulatory** 

*ASCO-lncRNA* Lateral root development Alternative splicing

**mechanism**

dynamics

regulators

Antisense transcription

interference

modification

association

re-localization

re-localization

enhancer

interference

**References**

[77]

[67]

[68]

[27]

[79]

[61]

[66]

[80]

[81, 82]

[28, 54, 78]

**Sr. no.**

7. *Solanum lycopersicum*

**Table 2.** List of some annotated lncRNAs.

**Species name Annotated** 

120 Next Generation Plant Breeding

**lncRNAs**

1 *Arabidopsis thaliana APOLO* Auxin-controlled development Chromatin loop

2. *Glycine max GmENOD40* Nodule formation Protein

4. *Medicago truncatula MtENOD40* Nodule formation Protein

*LDMAR (P/ TMS12-1*

5. *Oryza sativa Cis-NATPHO1;2* Phosphate homeostasis Translational

*asHSFB2a* Vegetative and gametophytic development

3. *Hordeum vulgare HvCesA6 lnc-NAT* Cell-wall synthesis siRNA precursor [69]

6. *Petunia hybrid SHO lnc-NAT* Local cytokinin synthesis dsRNA degradation [84]

*COLDAIR* Flowering time Promoter

*COOLAIR* Flowering time Histone

*HID1* Photomorphogenesis Chromatin

*IPS1* Phosphate homeostasis Target mimicry [46]

Fertility Promoter

*OsPI1* Phosphate homeostasis Unknown [83] *OsENOD40* Nodule formation Unknown [26]

*TPS11* Phosphate homeostasis Unknown [85]

Plant lncRNAs are known to increase the complexity of transcriptome and proteome by participating in alternative splicing. It was first reported in Arabidopsis, where lncRNA behaved as an alternative splicing competitor (ASCO) [67]. Together with the nuclear speckle RNAbinding protein (NSR), ASCO-lncRNA forms an alternative splicing regulatory module. The expression of AtNSR in primary and lateral root meristems regulates the development of lateral roots. The interaction of AtNSR with overexpressing ASCO-lncRNA affects the splicing pattern of mRNA targeted by NSR in transgenic plant [67, 87]. This indicates the role of lncRNA as a regulator of alternative splicing.
